Why Do Mainframes Still Exist? What's Inside One? 40TB, 200+ Cores, AI, and more!

[@stevekristoff4365]

DDR4 RDIMM memory is 3200 MT/s at 64bit (or up to 72bit w/ ECC) which 8bits/byte would give you 25.6GB/s. what you are missing is that memory is multi-channel. Intel Xeons can go up to 8-way memory, AMD Epyc can go up to 12 way. So you're talking 204GB/s or 307GB/s. DDR5 RDIMMS are even faster so throughput would be greater. What I do not know is the inherit latency of memory access (core to core, or package to package) where I suspect the mainframe would be better (lower latency). Is main memory on the z16 static ram or dynamic? Likewise PCIe I/O is up there on server platforms, a dual processor AMD Epyc has 128 PCIe lanes (Gen 4 for Milan, or Gen 5 for Genoa) for a total of 256 PCIe lanes of generation type. However should be stated that just pure lane counts does not compare well. Mainframes are set up to OFFLOAD a lot of signal & I/O processing much more than mid-range/server. (concept in the server world is just taking hold with dedicated processing units (APU/DPU) but mainframes have been doing that forever. There are a bunch of other items as well, but it's like comparing an armored personnel carrier to a car. Both can get you from A to B but one is much more robust. :)

[@DavesGarage]

Steve is correct! And the odds are there are other factors and subtleties that make such a comparison of questionable value anyway. But unless they let me benchmark it... :-)

[@tanjbennett4572]

The Z16 has plenty of local DRAM. That robot around 14m is inserting DDIMM (not DIMM) modules. They work with a transactional interface called OpenCAPI (aka OMI in a simplified version) that runs around 32GB/s full duplex compared to DDR4 25GB half duplex, and the Z16 chip has a lot of those channels (they are lower power and take up half the silicon on the CPU chip of a DDR4 channel). So that bandwidth is additional to the distributed "virtual L4" comprised of idle borrowed L2 capacity. As the L2 cache is SRAM it is likely significantly lower latency than DRAM even if it is in another CPU.

[@willd0g]

How does the Apple MacBook Pro M3 max compare

[@rolux4853]

@@willd0gis that satire?

[@willd0g]

@@rolux4853 you got me. What’s up with using windows XP (embedded). I was told the world ran on Linux!

[@dragunzonline]

I work on IBM Z and POWER as a chip designer. Awesome to see our work presented.

[@monad_tcp]

How do you get a job designing microchips ? just go for Electrical Engineering course ?

[@Brahvim]

​@@monad_tcp ...It's more about electronics than electricals. The specific _course_ would probably be computer engineering. Let's wait for the original commenter to offer further advice.

[@tim3172]

@@monad_tcpCheck out Google sometime. They can answer inane questions like this. 45 seconds: Computer Hardware Engineering majors. Oh wow, look at that.

[@JMiskovsky]

Total CHIP chad :)

[@JMiskovsky]

Any chance of using CAPI / Open Interfaces?

[@frankbosco293]

I retired in 2020 and I refused to work on z16 because it would have kept me working to age 81! But I was a z system architect up thru z15 and had worked on the mainframe since the system 360 model 85 which contained the very first memory cache. I always knew I was on a team working on one of the most truly great products ever conceived. I loved this presentation. Thank you.

[@douglaswilkinson5700]

I started on an IBM 1401 in high school then an IBM S/360-91 at UCLA. Joined IBM as a Systems Engineer. I installed 3033s, 3084s and 3090s, etc. It was an amazing journey!

[@daviddrumm3673]

The 360-85 was years ahead of it time. I assisted with hosting several corporate benchmark sessions at the Kingston plant in 1969 before it was withdrawn from the market because of its speed. Years later I had a occasion to work on a 3033 and realized it was just a 360-85 with faster logic chips, solid state memory and a CRT console. Like others here, I have worked on 1401 1410 1460 360 370 and 4300 systems. Plus 20 years on PCs from about 1990 to 2011. Now running Proxmox and Truenas in my retirement lab. Lots of GREAT memories!!!

[@mrice3274]

Graduated college in 1968 wirh a BS in Computer Science. It made a great career on IBM Midrange - System 36, 38, and what is known as IBMi (last I heard anyway). It was quite a ride that lasted >50 years. It would be interesting to see how it would stack against the Z

[@mrice3274]

Thanks Dave for all you do!

[@T3CKsnipes]

Dave, was a pleasure helping give you a tour of the Z manufacturing floor! Absolutely love this video!

[@DavesGarage]

Thanks for taking us ALL behind the scenes!

[@douglaswilkinson5700]

2024 is 60th anniversary of the IBM System/360.

[@larswillsen]

As an assembly coder since the late 70s (8088) its fun to see where we are in 2024 🙂

[@marktwain5232]

Thank you so much, Dave, for this fascinating tour! Now retired, I worked 41 years as an Application Development Software Engineer in the barbarian Microcomputer Revolution of the great unwashed out on the vast steppes. I always wondered what was still going on high up on Mount Olympus in the original Birthing Power Mainframe World! Now I have gotten a glimpse of the still evolving Sacred Temple! I absolutely LOVED this! Kudos to all of you Mainframe Engineers and Technicians commenting on this thread who worked in this World in the lofty Clouds! Homage to all of you!

[@computerpro123abc]

IBM OS = 1980 OS + LINUX TACKED ONE TO RUN WEB SERVICES.= NOTHING SPECIAL, JUST A LINUX BOX

[@alexhiatt3374]

This is INSANE, every time you mentioned a feature I thought there was no way they could top it. And then they're just casually like "oh yeah and these 64 5.2GHz cores can also run 2 bajillion VMs and encrypt all of main memory and correct for cosmic rays"

[@jovetj]

I haven't touched a mainframe in a little over 20 years, but.... _"when it just HAS to work: mainframe"_

[@Serpensin]

@@jovetj Because I got an earworm from that, I need to share it with you. I'm standing in your server room 'Cos I got kicked while playing Doom The lights are dim but I can see Your hardware is so quality I need to apply the patch So I can get back in the match But something's caught my eye A mainframe reaching to the sky

[@AllenCavedo]

Did you catch the brief comment that they can upgrade the mainframe firmware/software in place without shutting down?!

[@essentialworker3438]

hes an under utilized resource the universe hasnt tapped yet

[@jovetj]

@@AllenCavedo Yes. The system I worked on was a small business server, and I restarted it weekly, but if something went wrong with it we usually wouldn't even know, IBM would just show up _out of the blue_ to fix.

[@ChaosNebulai]

I remember saying "why do we still use those old things" not so long ago at my job, I have never been more humbled.. what a machine

[@jovetj]

People have been predicting the death of the mainframe for a long time-3 decades, at least. It's not coming anytime soon. It's just too easy for people to poke fun at or write off what they do not understand.

[@MaximZemlyanoy]

​@@jovetj the problem is it's very expensive to move out. It's not a question of benefits, but expenses and risks 😅

[@briansomething5987]

​@@MaximZemlyanoyabout half of mainframe workload is now Linux. And much of the z/OS workload is now Java. It's time for this "it's top expensive to move" meme to go away

[@saultube44]

@@briansomething5987Linux is good, Java is 💩, Apache should use Zig and Bun, no need for a Dinosaur, Linux should be done on Zig for even more Performance

[@jamesbrooks9321]

if only it were that simple lol@@briansomething5987

[@thecodemachine]

I am proud to have worked on the I/O subsystem code. I even updated the boot loader which was originally written before I was born.

[@DavesGarage]

Very cool!

[@willd0g]

What language? Legit question - would take a stab and say COBOL perhaps?

[@oneeyedphotographer]

@@willd0g Assembler I expect. Operating System components were written in Assembler in my day, and IBM used PL/S a lot, and later PL/X. Both could GENERATE(inline assembler code).

[@maxpowerlive8852]

why do you /ibm use win xp

[@kevinfleischer2049]

@@maxpowerlive8852 Its for a machine. Empedded XP. This thing works and does one job and only one job. Why change it? Chances are, this thing doesn't even have a network connection - and IF it has, surely no Internet connection.

[@charlesnicholas4758]

I worked on IBM mainframes for 25 years as a systems programmer. Great video that brought back a LOT of memories. Thanks.

[@jeffrey1025]

I work at the Poughkeepsie facility you visited. It's very cool to see you here as you were one of the first channels that I ever watched when I started building computers many years ago. And now I'm working at IBM to put myself through school. Thanks for inspiring Dave!

[@TomCee53]

The first machine that I was responsible for as a system programmer was an IBM 4341 back in the early 1980s. It was used for software development and testing running VM/CMS and supported 6 concurrent users. They’ve come a long way.

[@judewestburner]

Now you're looking at 7 users with 4 tabs each on Chrome. How far we've come 😄😄

[@Doesntcompute2k]

We had some baby 4300's--41, 61, 81. A 4341 could easily support 30 or 40 users in VM/CMS 370 without a sweat. We even bonded two 81's together with one as a "real system," and the other as a "test dummy," running loads and having the 2nd frame testing responses. Basically debugging one mainframe from another! LOL Our "big iron" was 3033s, 3081s, 3084s (replaced by 3090s). Cool toys! And we even have a baby 9370. I miss those days and the cold DC room.

[@oneeyedphotographer]

Six sounds pretty few, we had 70 or so on a System/370 Model 168. Under VS2 Release one, all TSO users shared a single address space and swapping was painful (3330, 3350 DASD). When we got OS/VS2 (MVS), everyone had their own and things were fine. In Australia, the 43XX computers had special firmware available to allow them to run Fujitsu operating systems, OSIV/F4 and OSIV/X8.

[@billb6283]

@@oneeyedphotographer Interesting. Hadn't heard of OSIV

[@pauldunecat]

Company I worked at the 4381 was the local branch machine, anything really needing processing went to the remote 3090/600S. The VAX/780 was used for DTF and ascii/ebcdic conversions. Now I'm all nostalgic about loading tapes/carts. lmao

[@carlbroker]

Data Scientist at IBM here, 1.5 years in. You nailed the current tone of IBM. Aren't they AWESOME?!

[@marred2277]

Looks like they even changed their dress code. Interviewed with them back in the 90's and was rejected because my suit jacket wasn't the right color.

[@oneeyedphotographer]

If you have access to the source code of Assembler H and scan for my initials, JCS, you might find evidence I was there. I also did work on PL/I and LE/370, but that was mostly testing and I didn't get to make my mark.

[@jovetj]

Yes. Mainframes are awesome, and they have been for 53+ years. IBM hasn't always been that awesome, but they have sure kept their eyes on the ball as far as their core product.

[@ibubezi7685]

@@marred2277 Maybe that is one of the reasons they completely lost their dominance? Wrong focus, trivialities, not adapting?

[@PatrickDKing]

@@marred2277 Yeah I interviewed a while back and I remember feeling it wasn't really up to snuff with the more modern companies, perhaps "progressive" is the word. In any event I wasn't impressed.

[@JoseGustavoAbreuMurta]

I worked at IBM Brazil for 36 years until 2015, including mainframe maintenance. What impressed me most was when I changed memory cards on a large PSeries server with the system running. Thank you for bringing us up to date with the new IBM ZSeries technologies!

[@billgoodman7403]

HOW MUCH SMOKE DID YOU SEE?????

[@tanjbennett4572]

You overlooked a key reliability feature .. the IBM Z series includes extensive internal self consistency checking of the logic inside the CPU so it can detect when the logic fails and retry a transaction, shutting down the core if necessar. "Commodity" CPUs are tested after manufacture but after passing test most later errors are silent. Recent testing for silent errors in servers at Google and AWS have found that silent errors are quite significant. IBM has taken them seriously for decades.

[@RayJorg]

That is one of the most important features, and also one of the most important differences between mainframes and micros. The US government has a huge set of operating guidelines that must be met by the bank's IT departments, and I'm out of date on that stuff, but those generic CPUSs probably don't pass those guidelines for certain transaction processing.

[@michaeldavis6607]

I am a long time programmer analyst on an IBM power machine but I still call it AS400 . We are a loyal breed to these machines. They perform so well.

[@jerseybob4471]

WOW! Quite a system. I started working at IBM in 1967 and retired in 2005. My first IBM system was the 360 model 50. It had a single 32 bit CPU and weighted 3 tons. The max RAM was 512KB and four I/O channels. The CPU cycle time was 500nS. RAM speed was 2uS. It managed about 200k instructions per second. We’ve come a long way baby.

[@ronaldlee3537]

In my days as applications COBOL programmer, I used a 370-158.

[@ArneChristianRosenfeldt]

32 bit 2 um is the same memory bandwidth as on a C64 from 1982. 512kB is as much RAM as in Atari ST from 1984 .

[@uis246]

360? I think my dad worked on soviet clone of 360 when he was in university.

[@dont99999]

I started on a 360-30. IBM used to supply a Systems Engineer along with the machine back then. Lots has changed since then. It was quite an interesting field to be in.

[@dmitripogosian5084]

@@uis246 ЕC-1022 ?

[@davidfirth1]

I grew up in a mainframe family. Dad was 40 years at Burroughs/Unisys. I was a co-op electronics student at IBM, then worked summers at Burroughs/SDC/Unisys. My now employer of 30 years relies on IBM big iron, and the young folks coming in have no idea. All they see are the apps that still run green screens, not the heavy lifting happening behind the scenes. Thank you for this episode.

[@SenorJohnMega]

Your channel gets better and better! Thank you for making such interesting content and sharing your own life and experiences. I appreciate it very much.

[@DavesGarage]

You are so welcome!

[@knerduno5942]

But why is Dave never in the garage?

[@theradioweyr]

@@knerduno5942 Because after Dave started making more money on his KZbin channel than his wife explaining these things we lie awake at night wishing we understood or knew someone in the business to keep us old farts up to date he is not no longer confined to the garage.

[@eplazai]

You’re unstoppable, Dave! Hearing an engineer like you talk about mainframes provides invaluable content. Thank you for sharing your knowledge with the world.

[@PeterBacon]

Better than hoarding

[@lisander-lopez]

As a software engineer for z/VM , you really DO get impacted by ALL of these things. The way you handle I/O failures, System failures etc.. in the code, is crazy. Came from being a web developer. From React/NextJS/insert JS framework here to PL/X and Assembly. I went from high up in the stack to relatively low on the stack.

[@SaMuEaL0707]

@lisandro-lopez would like to know more about it from you , i wanted to start my career in Mainframe !!

[@jaybee9708]

This is fascinating. I was a programmer on IBM systems for many years before commoditized systems took over most processing tasks in many businesses. It's nice to see that mainframe systems are still relevant and that deep-dive security and fault-tolerance are pursued with such meticulous zeal. It's also cool that this is still being done in the US. Thanks so much, Dave, for producing this.

[@jej3451]

It's no coincidence that this is being done in close proximity to Wall Street.

[@monad_tcp]

well, you look at 13:14 and now you know why. some things need to be really really reliable. what happens to a normal PC data-center when there's such an event ? the entire data-center needs to fail-over to another entire data-center. You can't just keep working because of annoyances like earth-quakes.

[@MrHav1k]

One trend I'm noticing in these comments is a lot of "was" and "now retired" people. What are the prospects of these systems going to look like in the near future when the next generation of techies coming up won't know F all about languages like COBOL, etc.? Who will maintain these applications in the future?

[@tracye3586]

DONT get all excited they moved most manufacturing to Mexico I think

[@TheChillieboo]

the reason your videos are SO good to me is that the parts i dont fully understand are still entertaining, i i think thats due to your delivery. no clickbait , no artificial suspense , just solid presenting. love it!

[@tomhutton9522]

Being a retired guy who started out as a customer engineer on RCA IBM 360 compatible mainframes your video brought back many memories. As years went by I supervised an IBM customer system programmer group whose responsibility, amount other things, was to evaluate vendor hardware, mainframe and peripherals. As part of the evaluation we made many trips to IBM and other vendors around the country. We did an anual trip to Poughkeepsie even stayed at the IBM homestead a few times. I was even part of an IBM customer council looking at proposed new technology. Anyway, your KZbin series is a great source of current and past IT technology. This video was a surprise in that it covered technology very few are exposed to.

[@ArtifexBarbarus]

I once spent a week in the Twin Cities at Unisys' HQ to get trained up on their "new" class of ES7000 mainframe servers that were optimized to run Windows Server 2003 Datacenter edition - While touring their company museum, my tour guide asked if I "knew the difference between and IBM mainframe and a Unisys mainframe", I shrugged and he gleefully said "Unisys mainframes suck, but IBM mainframes blow!" He then explained the difference was their liquid cooling, in which a ruptured hose in the IBM mainframe would cause the coolant to spray the inside of the chassis, whereas in a Unisys, it'd just leak on the floor,

[@jerrygentry2348]

I worked for AMEX and then IBM and fully understand a) how and why a mainframe fits particular market segments in a way no other computing environment can and b) just how committed and dedicated the IBM team is. Thanks for this review. It is such a mind boggling presentation and you handled it well. I definitely don't understand a lot of it, but I do understand the why of it.

[@swoopsavvy7560]

Their fill station still runs Windows XP. I guess when you absolutely positively need your fill station to work every time, you only rely on the very best. The way you put this Mr. Dave. Brilliant!

[@jrstf]

I remember a 1990s news story buried by most news services, US Navy outfitted a ship entirely with Windows XP, in control of everything. Maiden voyage and all computers blue screened leaving the ship dead in the water, they had to tow it back to port. Fortunately it wasn't in war time.

[@brianvogt8125]

@@jrstf XP was released in 2H 2001. If you're referring to Windows 98 (first edition), that would be believable because it crashed with a BSOD during the full press demo of plug-and-play.

[@oladunk9986]

@@jrstf If I remember correctly this fiasco was caused by some early Windows NT. An incorrect manual data entry on a keyboard caused the complete ship to shut down and it had to be towed back to port. It was not possible to restart the engines.

[@alanmon2690]

If my deteriorating memory is right then a university professor found the XP system would crash at intervals because a 32 bit counter overflowed(?) I think it was about 7 days.

[@tim3172]

@@jrstf"Buried by most news services..." or, as an intelligent person would say, "not reported because it's not exactly newsworthy to the vast majority of people." But sure, it was "buried".

[@MikeHarris1984]

My company is the largest financial institution by assets and I joined in 2007... the funny saying that management says every year during planning... The mainframes are on their way out. Then every few years we do a massive mainframe upgrade lol... Those things are beasts!!! They chunk through data faster then anything else. You have to do a ton of custom integration, but damn, are they massive processing powerhouseS. When the micro second counts to make money in trades and bank transactions, nothing beats a mainframe. That single drawer is just one part. The mainframe is the full cabinet. You customize it by each drawer. In each of our data centers, we have MANY of the full Z frame setups. They are enormous and the redundancy is insane.

[@mephInc]

You working for blackrock?

[@MikeHarris1984]

@@mephInc nope, black rock owns damn near everything. But we work with black rock and at our annual RIA conference that my company puts on (and I owned and engineered the technology for the event for 7 years) over 800 desktops, 400 laptops, 2000 monitors, two racks of full mobile servers, blades, SAN, networking in a rack. Where in the rack we would run around 30,000 virtual desktops that would build on demand and deploy for items and destroy after. At any time, 3,000 vdi desktops running, about 30 virtual servers running the back end systems and network capacity of 4, 10Gbps fiber links fully redundant running from 4 different isps, and setup a funny NOC/SOC onsite, and lots more. Now I'm out and moved on from that stress, but they run a lot in cloud now that we've started some implementation into that area. But we are the largest financial institution by assets, as in customer money in accounts. With our combined Acquisition we made 2 years ago and just on the end of finishing integration, nearly 11 trillion under our management. Official is 8 trill because of they are not finished moved over yet and the old name we purchased to go bye bye in history. Been with this company since 2007 when I was 23. Started as a contractor doing 21" CRT to dial 15" LCD monitors in two buildings here of around 9000 employees. And moved to support, then took on engineering and built and designed our VDI deployment of 12000 virtual desktops for offshore and retired our old HP blade computers (like a rack mounted laptop where a chassis had like 25 of them. And moved on to desktop engineering and then to security when we formed our new security org, then to various parts where I owned the products and built security policies and procedures and deployed a full rdp/ssh/admin (secondary) account vaulting and session management, recording, keystroke logging, monitoring and review, etc... and then to lead architect. Literally started as the lowest on the tottem pole and in my 16 years there, moved up to sr manager and lead solutions architect of some of our more sensitive security infrastructure. Lol, and since day one... mainframes will be out in the next 2 -3 years, we are retiring them! But nope. There is just things that with active customer trading, world wide bank transactions, batch processing, and much much more, that a mainframe can do in a micro second with 100% accuracy that a computer or server can't. And when a milisecond is the difference of tens of thousands of dollars, they are worth their ungodly price tag. (Millions spent yearly on them for support and maintenance and IBM has staff onsite that their job is to sit and if something breaks, for it right away. And a new unit is multi millions when you factor in power, cooling, data center floor space, setup, configuration, migrations, fibers, interconnects, etc... it's mind boggelinging

[@mephInc]

@@MikeHarris1984 Nice to see you work your way to the top. Something most kids today can't comprehend lol.

[@theprojectguy2341]

Same at my financial comoany. MF is a dirty word. I think its cultural. The new sexy buzzwords get the attention, but all trades still clearing via the MF

[@marktwain5232]

Fascinating to me as a Career Microcomputer Architecture guy! I would love to see such things!

[@flyingjeff1984]

Dave Cutler. Now this? You're KILLING it.

[@mitchellstl]

Thank you Dave for the in-depth tour. As a software dev for over 25 years on the mainframe, it truly amazes me at the vast raw horsepower that the mainframe has. Job well done on the BTS of the Z series.

[@sr6424]

Worked originally as a COBOL programmer on IBM MVS mainframes. Many career changes I finally left the Mainframe behind in about 2000. Found this interesting. I watched loads of organisations move away. Great to see they are still around!

[@KangoV]

I worked on an AS/400 back in the 90's. One memory was coming in on a Monday morning to greet an IBM engineer in reception. He said that our AS/400 had suffered a cache problem over the weekend and had contacted them for help. He opened it up, replaced the CPU cache board and closed it. The system basically said "thanks" and it proceeded to speed up to full speed. Absolutely astonishing. And that was over 30 years ago.

[@neriozulberti1492]

PWRDWNSYS😊and PWRONTIME(*SAME) PWROFFTIME(*SAME) I remember those good times😊

[@neriozulberti1492]

After decades big blue confirm great products with great engineering

[@KangoV]

@@neriozulberti1492 Yep. Also look at IBM Northpole AI/ML chip. 6x faster than NVidia A100/H100(new) whilst being more efficient.

[@phildoucette7603]

Thanks for the mind-blowing specs. I wrote my first program on a IBM 370 in 1972 in FORTRAN and have been hooked for life. Interact and JCL were my friend.

[@arlipscomb]

I started my IT journey on the Burroughs mainframe. The "Large" flavor (or "A Series") was a marvel in its day. Based on the first virtual memory, multi-processor architecture the CPU was a non-Veneman design that was optimized to run the ALGOL programming language. Like the IBM machines, these were reliable, and had massive I/O bandwidth.

[@oneeyedphotographer]

Sign and magnitude binary numbers, programmed in ESPOL.

[@mikeklaene4359]

In 1969 I landed a programmer trainee job at a department store in Cincinnati. We had a 32K 360/30 running 360 DOS and Assembler was the first programming language I learned. After being away from mainframes for 20 years, I applied for a position at a shop that had 6 System 390's. The hiring manage asked if I thought that I could still do assembler - I said if "D2" was still the op code for the MVC instruction - then yes. He was surprised that I knew most of the op codes and could even read a core dump.

[@Morggin]

When I went into the USAF in 1993 (AFSC 2E231), I spent almost a year at Keesler AFB learning component-level troubleshooting and maintenance of the old Sperry mainframe that still had spindle hard drives, punch card readers, and large reel-to-reel tape drives plugged into it. Boy, how times have changed. Of course, by the time I got my first PCS to McChord AFB, the 62nd Communications Squadron was actively pulling the main frame out of service and replacing it with Novell 4.11 servers and Windows for Workgroup 3.11 on Zenith Z 386 workstations.

[@bubbavonbraun]

I/O Transfer rates was always the differentiator, the amount of data they could move was huge compared to Mini's and Micro's.. Add to that the focus on reliability and the culture that runs through most of the Mainframe folks on high availability it remains a substantial weapon. Never worked on them but working with a major bank had to back-end our Internet banking to Hogan on the mainframe as you say its always has to be there. Love your reference to the cosmic ray memory flip, I have used that for years to explain to random reboots. Dave you keep reaching new levels in your content please keep it up.

[@m1lkb0n3z]

This was so much fun! I cut my programming teeth on System/360 in the days of punched cards. We threw a little party in the computing center when we added the second megabyte of core memory. Next came Control Data mainframes (two 6600's and a 7600) at a national accelerator lab. The modules on these machines made electrical connections to a backplane, but also freon connections to the refrigeration unit. Things have come a very long way since then, and it's good to see that IBM is still in the game.

[@garycartwright8488]

Dave; thank you for bringing us along on your journey through IBM's new mainframe. I joined IBM in 1958 as a Field Engineer on a computer system IBM bult for the US Air Force used for air defense called SAGE (ANFS-Q7). The computers (each SAGE building had 2 mainframes for reliability) were housed in a 3 story building (with major air conditioning) and each computer had 68,000 vacuum tubes. Main Core Memory (RAM) was 64K of a 33 bit word, and the system ran on a 6 microsec memory cycle. Following my time in SAGE I returned the commercial business word and I worked on 1410/7010's in Boston. Then 360 models 30, 50, and 65. Then I was transferred to engineering in Poughkeepsie and worked in the 705 building supporting reliability on the 303x systems.. So what a journey when I compare the Z16 to my life with mainframes and PCs (I still build PC's once in awhile). Thank you - Fascinating (and I wish I could start over again with a Z16). How much maintenance is required for one of these?

[@davetdowell]

> How much maintenance is required for one of these? Not a lot, they basically very rarely go wrong, and when something does it can be replaced in flight generally.

[@sjfsr]

I finished 3 degrees in computer science and it's nice to have channels like this one to keep my knowledge fresh.

[@stonelaughter]

I'd be interested in seeing what they do with the operating system; how they partition the workload, how the mainframe itself is maintained and run...

[@oneeyedphotographer]

In the late 70s I had access to a System/370 model 168MP. MP meant two full CPUs configured as a single computer. One evening I dropped in, and after a short conversation it was agreed I can have my own computer for a few hours. Without interrupting the workload, I showed an operator how to separate out a CPU, some RAM, a channel, some DASD, a 3270 controller so I could have a console for doing stuff. Then got out my 3330 disk pack and ran OS/VS1 for a few hours, doing a SYSGEN for our computers. When it was done, I showed an operator how to put it all back together. Back then a CPU alone occupied a whole box, and there was another to connect the two CPUs, and each channel also had an equally large box. I had to read the numbers on the sides to see what was what.

[@jovetj]

One thing Dave did not really cover (maybe because he didn't work on them himself) is that mainframes are a whole other world of computing. Sometimes you just have to forget what you think you know. Many of the same terms are used, but in different ways than you might expect. Partitioning is a key aspect of mainframe architecture. The bare-metal partitioning mentioned is called an LPAR. I'm sure you can find more details about that by searching for that term. A mainframe operating system can then soft-partition available memory to different tasks. This essentially contains each process. Each program running at any given time runs in its own [memory] partition. In the frame cabinet, behind the front door, there is one or two laptops that are affixed to the frame to be opened up and used. This is called the Support Element and is the lowest-level access to the complete machine's operation and status. Satellite computer(s) outside of the frame called the Hardware Management Console can do many of the things the SE can, but over the years the distinction has gotten less and less. If you wanted to turn on or reboot or partition the mainframe, you would use the HMC or SE. As mentioned, when failures happen, a hot backup instantly kicks into place, and IBM is automatically notified so a repair will be scheduled. Edit to add to my comment: The zSeries and z- mainframes are a complete 64-bit architecture. They also started out being fully backward-compatible even for old software written in the 60s. Some of that very-older comparability has been removed or minimized in newer z- models, but backward comparability is a huge assurance to customers.

[@nICkY2099108]

Well i have worked for a long time on the software implementation end for IBMs os and other servers and know that they configure storage devices and use mount points directly to deploy oses, they are tricky to configure, I have not configured personally but I have worked on these mount points or something they called luns to setup our softwares, they even have replication directly from the storage itself

[@statinskill]

Get the Hercules (softlabs) emulator and you have a S/370, S/390 and Z-ish mainframe enough to run even z/OS and z/VM. Then go on a quest and hunt down the dasd images of whatever OS/390 or z/OS you can find. Then hunt down the documentation. Start reading the MVS and JCL book from Ranade publishing. Be prepared to read the IBM manual "Principles of Operation". This manual started in the sixties so start with the manual for S/360, that most amazing family of machines. You can also get started right away with a public MVS 3.8j distribution that is actively maintained by the community. Now you have enough to get started, you could start learning about JCL in about an hour and submit your first assembly job to MVS $HASP today.

[@da-voodoo-shuffle]

The redundancy around the Storage is quite impressive. You can lose a disk array in one data centre and its replicating counterpart in another data centre can take over the workload without it impacting on normal IO on the mainframe... Just an increase in IO read write time due to the change in distance when going cross site.

[@rodneymkay]

I'm working in a job where I get to write code that runs on these (well, in our case, we recently upgraded to z14, but still cool). Really cool video to finally get to see what these actually look like on the inside. I only ever really interact with them through IBM Reflection (Terminal).

[@dave7f611]

Well said, Dave. The best feature for me personally has been job security since 1983. 4341 through z14 (so far).

[@steveschein2619]

Wow! I started playing with electronics in 1969 (Heathkit), built my first radio in 1970 (Tandy), bought my first computer in 1982(C-64 I still have) and started EE school in 1989 after playing around. Watching this still amazes me. Where we have come in just one lifetime leaves me speechless. My son is at the Naval academy in Annapolis doing EE. What is he going to see in his lifetime? (okay, I started him in computers on the C64 :)). Thanks for the video. Keep up the good work.

[@johnwalker6121]

You mentioned virtualization, fortunately I was a IBM Systems programmer at the dawn of it's introduction. Worked DOS, DOS/VSE (skipped SVS & MFT), VS1, MVS and ZOS. The early days technology and software were much less mature/sophisticated and more like the wild, wild west. While up-time was relatively good it was nowhere near current reliability standards. Enjoyed your presentation and since I'm retired no longer cringe when the phone rang at 2am from the computer operations center. :-)

[@Iforgotme]

I got a few of those 2am calls in the 1960's on DOS,DOS/VSE. Always a new challange. Loved it. Moved on to VM/VSE. Retired in 2000.

[@grahamr56]

I started my career as an operator on Burroughs B3500/3700, ICL 2904 and then moved into IBM S/370. Eventually I ended up in Sales, with Novell, Cisco and Oracle, and I've watched as things changed to cloud, containers etc. But having worked on those mainframes is like a badge of honour. You were part of a very small group of specialists in an emerging industry (and back then many of us had no idea how big it would become).

[@rwh777]

A Burroughs guy! Hello. The first computer I ever used was a B5700 at my uni in 1972, I loved that machine. My degree was Applied Math and Computer Science and my career remained in the Software Development area.

[@universalyardbird]

I started on Unisys A Series then operated B2900s. Your story looks similar to mine (see my top level comment).

[@universalyardbird]

@@rwh777 yes, I’m definitely an old Burroughs dude. In fact, my first exposure to a Burroughs was in my High School Data Processing class, where I wrote, compiled and ran my first ever COBOL program on a B80-31/131. That was 1979 and some years later, my lead op from work brought an old B80 to my parents house where we attempted to re-wire/resurrect it from the grave (it originated from a surplus auction that my supervisor’s friend/neighbor had procured). Long story short, it didn’t pass its IPL and the external hard drive (about the size a clothes dryer) made a horrendous grinding noise. Oh, it also nearly blew the entire circuit box for my folks house. Haha, those were some great times. No Internet, no cellphones and the only personal computers were the ones you either built from Heathkit or spent a small fortune on an IBM.

[@harryfarnuckle5307]

My first job interview was with Burroughs in 1981 where I had was shown a mechanical calculator and was required to explain how it worked. Thankfully I didn't get the job and was employed by IBM a month later. Great company to work but sadly they totally stuffed up the PC market opportunity in the early 90's.

[@roadie3124]

I joined Burroughs in 1970 in the UK, starting on L/TC Assembler. By 1972 I was doing systems architecture and project leading/management work and the actual machine didn't matter all that much. I was working at the Burroughs World HQ in Detroit on and off from 1972 to 1975 and emigrated to Australia in 1976 working for Computer Sciences Corporation. I found myself working with B7700, IBM 370/168 Univac 1100, and a bunch of other stuff. I worked for Digital in the late 1980s. It's been fun.

[@jrherita]

I love the pure brute force approach of these chips and hardware. I do see Epyc using some more advanced technology though lately - TSMC N5 and stacked 3D cache for >1GB of cache per socket. But that’s still not as complete of a caching solution as what these mainframe chips can do. Thanks for the tour Dave!

[@monad_tcp]

The die size is HUGE

[@monad_tcp]

Think about the absurdly low yield IBM has on those chips and how expensive they must cost. Low yield means a lot of refused chips when manufacturing because of defects, it must be absolutely perfect, which is very hard for a chip that big. They probably don't even do binning.

[@oneeyedphotographer]

@@monad_tcp That's why they have spares.

[@mieszkogulinski168]

@@monad_tcp maybe they disable failed cores or cache segments?

[@lorensims4846]

I've worked on several mainframes over the decades, but always remotely. I've never actually seen one. Thank you so much for the tour!

[@unfgreen]

I've worked in IT 30+ years, and learned more in this video about mainframes than I ever thought knowable.

[@thebunyip]

Wow. Dave is awesome. Best IBM salesman whose pitch I have heard in years. IBM salesmen were fascinating - targeting their focus on $ or technical stats depending on audience to sell mainframes or to move to the next level system.

[@joestroup5058]

I was a MVS systems programmer back (way back) in the 80’s. It would be really interesting to me to know something about the OS environment(s) running on these things. I get it about the virtualization capabilities. But there is still something managing them. Thanks Dave!

[@davetdowell]

Microcode, the MCL (on the SE) loads microcode (in POR) that creates the environment for the Image (LPAR). Your Image then has an environment with channel access to storage to load an OS from (IPL (Initial Program Load)). That's called IML (Initial Microcode Load), and until you've done that the Image environments don't exist. Once it's been done IPL for the specific Image environment becomes available. MVS has been 'rebadged' as is the current trend, to z/OS, it still looks and feels like MVS, so you'd recognise it. It's also had a whole lot of modification to make it more Java friendly and cloud capable. z/VM is the micro partitioning OS Dave mentioned, and is still quite common.

[@skurtz97]

Current z/OS systems programmer. For the most part, the base MVS part of the system is largely quite similar (except for of course an expansion in instruction set to accommodate things like 64-bit instructions and addressing). There's lots of new stuff too. Most POSIX compliant Unix programs can run natively now. So lots of modern subsystems will have an interface running under Apache for instance rather than VTAM (although the old SNA protocols still exist, and ISPF is still the most common way for systems programmers to work).

[@skurtz97]

They also run Linux of course under z/VM. That's been around since about ~2000. But z/OS / MVS is still probably more common.

[@captaindunsell8568]

One of the major advantages of the mainframe… is that the same size support staff for the OS is all of its software does not change from the smallest machine to the largest machine …. For example, a SSA, two systems programmer handle all of the zOS instances… all of your SSA interactions, including the Web interface is on Two machine geolocation diverse … 50% split use and dynamically back each other up … Two CPUs.

[@monad_tcp]

its almost as if they're doing all the heavy lifting of the entire operating system via hardware. (I know they are, this is rhetorical)

[@davetdowell]

So what you are describing is a SYSPLEX, a cluster of mainframe images (LPARs) running as a single system (the 50% split gave it away). The geolocation diverse line might make yours a GEOPLEX, so somewhere on your mainframe complex there will be a CF (Coupling Facility) that handles the Image to Image communications between the two physical systems (it might just be in an LPAR on one of the processors).

[@paolocanali3361]

This video is giving me some hope that IBM marketing/communication efforts on the midrange and mainframe technology will improve and will be more focused on the way information should be presented today. The effort I need to get IBM technology financed by management is way higher than the one needed for x86 computing, networking or security, because when people hear the mainframe word, they think to old dusty things that runs legacy code written for archaic programming languages that you access trough a text based console. Yes, mainframes can also run that kind of things, but most fo the time you need a mainframe to run very specialized tasks at state of the art level.

[@alexandermathar7780]

I was there in the summer of 1992 with my father Albert . It was quite impressive. We stayed two weeks in a lodge Motel in Fishkill, NY. Father started out as a programmer for IBM Germany, he then became programming instructor in the Training facility in La Hulpe near Bruxelles,moved back to Germany where he planned and designed high speed Networks .

[@CCP187]

I remember my first IT job in 1999 working with NT40 and wondering what was up with the ancient mainframe guys at my company. Now I'm the old man. Respect.

[@jaimeduncan6167]

IBM is doing all they can , in the last couple of years to attract new minds to the mainframe. I wonder if it’s too little too late. Something that this video did not have time to touch is software discipline. It’s one of the keys if the mainframe success story .

[@MitchMax5]

I have been in an IBM Z team for a little over a year now as a sysprog. It was pretty foreign to me as I am only 23 and had only done a little bit of mainframes at university. I wish there was more young talent coming into mainframes but we're trying!

[@willd0g]

@@MitchMax5 ill come join. I jokingly tell people at work I would love to live in the terminal. Engineering man makes it look fun also

[@danpatterson8009]

IBM continues to develop and build mainframes because there are customers who will pay for mainframe capabilities. If there were less-expensive solutions that worked for customers, customers would buy them instead.

[@MitchMax5]

@@danpatterson8009 There are less expensive solution, they are just not nearly as fast and powerful

[@MitchMax5]

@@willd0g My team is in australia. The engineering and sales of mainframes isn't really done here

[@Brainman365]

Great video thanks. I started my professional systems career as a mainframe developer in the mid-80s. It’s great to see they are still so relevant.

[@davidjowett8195]

Very informative. The environmental testing that the systems undergoes is astonishing for something that sits 'quietly' in the back room.

[@griffincorp7125]

Dave's intro was throwing some serious Jeff Bridges Tron vibes. Excellent video!

[@bhupendersingh8427]

Bravo. Ex IBMer here. I hope that IBM and the customers world over never lose sight of truly astonishing tech. Cheap commodity servers let your company make millions, but when the transactions are worth Billions, Mainframe is it...Thanks for the intro...

[@hessex1899]

I am frequently a target of derision for my love of IBM Z series. Mostly because the love of IBM's big iron somehow contradicts my 50something OG 90's hacker quasi anarchist vibe. My detractors are rubes and I feel about them the say way that Christopher Walken feels about people that don't like hot dogs. I haven't finished the video yet but given that you are doing it and given the subject matter I a preemptively liking it. :)

[@SecondSunofficial]

This is a great video! As someone who works at AWS in one of their data centers around their next gen servers, this was so cool to see what IBM is up to :)

[@c128stuff]

It is fun to see how much everything in that place still looks totally recognizable as an IBM site, eventho I haven't been inside one since the 1990s. Oh, and the entire build of those machines also looks very much like the IBM I used to work for. Cool stuff.

[@sorbpen]

This was Fantastic Dave! If you ever get the chance to be invited to anything like this again, please go for it! This was so informative, and with your own style of storytelling that we love so much. To anyone else thinking about offering to invite Dave, please just do it!

[@oldmandan3758]

Fascinating video. It's quite amazing to see how far mainframes have come. I just retired from a 40+ year career in IT. I started my career supporting MVS and VM on IBM 308x series mainframes. My primary role was to support VM/SP, VM/HPO and VM/XA for a decade along with secondary support on MVS and SNA networking. I left the mainframe world and moved to Unix and TCP/IP support in the early 90's. Seeing what a mainframe has become is astounding given I know the technology you described very well. Great work, Dave!!!

[@kc5402]

Thanks for another great video Dave. Very interesting. I started my working career learning COBOL on a Univac 90/70 for a UK insurance company, later they moved up to a Univac 1100/60. It's great to see a video that brings back a load of nostalgia for me! (Sadly I may not be able to watch your channel for much longer. Recently everyone on KZbin has been suffering much more harrassment from the company due to the use of ad blockers. If this continues, KZbin have said they will block me. But I will hold out as long as I can! Best Wishes from the UK.)

[@NotMarkKnopfler]

There is a browser available that can get around it. I can't name it directly as the comment will be auto deleted. However, its name is the opposite of "coward". It will fix your problem. I've been using it for over 5 years .

[@NotMarkKnopfler]

Hint: it would be a _brave_ choice. 😊

[@gothikia]

This was seriously cool! Thanks for doing this Dave and thanks to IBM for letting you guys in. Would love to hear the question and answers you previewed at the start of the video.

[@DarrenMossAU]

Great tour Dave, you gotta hand it to IBM for manufacturing world class computing for so long where other vendors have not come near the performance of these machines. Loved the shock testing, that was amazing to see equipment powered-on whilst being in a simulated Earthquake... and it continued to run! Amazing.

[@davidminear9163]

As a retired IBMer, I can say that this is one of the best mainframe overviews I have seen. And the dedication of the responsible IBM teams cannot be overstated. Well done!

[@garygrebus1602]

Fantastic presentation. I was in engineering at DEC for a number of years working on some of the larger systems we made. The dimensions of the problem are the same (speed, connectivity, redundancy, maintainability, etc), but the numbers on these machines are truly mind boggling. There are just some parts of the computing world where you need all the features these machines bring. And fun to see that the passion for building machines like this is still around.

[@rilauats]

30 seconds into this episode you already earned my thumb up. You're dead on target with this episode's core question (my creative alter ego rewrote your theme question) "Why a z16 instead of a PC with a 4090 graphics card and the perfect gamer mouse?"

[@OldMan_PJ]

I worked at IBM in 2001 & 2002, all I remember was white hallways, black door trim, and the occasional poster of sailboats, all lit by the cheapest fluorescent lights money could buy. One of the departments I worked in managed the office spaces in each building, we had one room in the basement we kept off the lists where we "stored" a ping pong table and mini fridge. At the Santa Teresa location (San Jose, CA) there was a twisty roadway that led up to a golf course that was popular with street racers, IBM had an aerial photo done of their buildings and you could see all the burnout marks on the street from the racers. The golf course clubhouse was a popular location for lunch.

[@Rybagz]

I used to work with mainframes, would be nice to get back to them. Back around 1988 - 512 Meg main storage (RAM), 4 CPUs totalling maybe 80 MIPS and a few hundred Gig worth of storage. Supposedly our first government department to exceed 1 TB of connected DASD did that in 1993.

[@oneeyedphotographer]

I started 20 years earlier. I recently spent a day scanning the latest equivalents to the manuals I used in the 70s. The assembler code I wrote then would still work today, i was going to say except for the loss of remote 3270 terminals, but I suspect those would still work. Provided I could cook up the appropriate (emulated) 270x controller. I had a 3704 back then.

[@jovetj]

Very nice! It's been about 20 years since I've touched a mainframe, but I was pretty much hooked.

[@pquirk99]

My Burroughs B5500 mainframe (circa 1968) now runs as an emulator in my browser. It supports 8 tape drives, multiple card readers and printers, card punches, datacomms and head-per-track disk. It supports full virtualization of memory and can easily run half-a-dozen ALGOL and COBOL jobs simultaneously in 32K words.

[@oneeyedphotographer]

@@pquirk99 48 bit words. The real thing didn't cope well with hordes of students trying to save their work in under 20 minutes.

[@oneeyedphotographer]

One TB. Barely enough to store my photos for 2022.

[@c4itd]

Thanks Dave. Whenever I watch your videos, you confirm a) it's worth to be a part of the computer history b) it's worth to learn. I started with an IBM 4361, learned all about Microsoft since DOS 2.x, Windows 2, 3.11, NT 3.5, SCO Xenix, Linux, RASPIs up to todays Cloud Systems.

[@BuzzCorrey]

I was an IBM Field Engineer, worked on System 360 and 370 mainframes. Found this to be very interesting. Much changed since my time in the field. Thanks for the video.

[@drewk3402]

Thanks, Dave, for another fascinating segment. Keep geeking out!! I love your in-depth peeks under the covers of computing yesterday and today.

[@JamesHalfHorse]

Last place I worked had a Z series running a medical records system. Mainframe itself was not in a standard rack just a huge monolithic monster but very stylish. Redundant everything including 2 racks filled with as many 1tb drives as they could hold. I think the whole thing required 6 50 amp circuits. Redundant power too. It was an amazing beast and thank you for helping me understand it better.

[@davetdowell]

It's important to understand the difference between a mainframe and an I/O device. What you are describing with this: > Redundant everything including 2 racks filled with as many 1tb drives as they could hold. Is an Enterprise Storage Server (likely a DS8000 series machine). Mainframes don't have hard drives (except for the management elements) They outsource I/O operations to control units (CUs) in I/O devices. So a mainframe doesn't store data, it gives it to a CU and says store that. The storage controller handles storing it and where and data protection measures. Latest Enterprise Storage Servers do sub 1ms response times. Imagine every card transaction that takes place being credit checked in real time as you do it (because it is). The mainframe (processor) software application requests the record from an Enterpise Storage Array and gets an answer back in less than a millisecond. So when you swipe your card, and it says approved, that went across the communications network to the mainframe, which processed it and requested the relevant records from a DB on the storage, the application checked the numbers and answers the credit check (approved/denied) and the application then responds back to the retailer, over the network. Whos card machine says approved/denied. That's happening realtime on every transaction for every card right across the world. 24*7*365. Mainframes for the processing, Enterprise Storage Servers for the data storage. It is such a volume of traffic that a £15 million upgrade in that system can pay for itself in a day of processing those kinds of transactions, because of the increased volume of transactions that the upgrade facilitated.

[@JamesHalfHorse]

@@davetdowell The mainframe itself was it's own beast. There were 2 other racks next to it full of IBM branded storage top to bottom. Fiberchannel stuff if memory serves it's been a while. I don't know what the full specs of the mainframe was but it was supporting about 20,000 total clients + printers.

[@tullochgorum6323]

When you consider the exotic complexities of building performant, reliable and secure distributed systems on commodity hardware, the mainframe still looks like an attractive option!

[@TheGreatAtario]

I bet it looks considerably less attractive when the bill comes

[@tullochgorum6323]

@@TheGreatAtario They start at about $2.5 million and head on up. But if you consider the salaries of elite developers and sysops plus the hosting costs of a large cloud infrastructure plus the reputational costs of lost data, it obviously makes sense in a lot of scenarios. Imagine if you are a bank. Do you really trust your core account data to some exotically complex sharded distributed setup? Or do you prefer to stick it on a couple of massively redundant replicated super-computers? Again, if you are a high frequency trader, using dozens of GPUs and striving for microsecond latency. As we've seen with real examples, the cost of a glitch can run to $billions and break the company. You're surely happy to pay for the fastest, simplest, most robust solution...

[@TheGreatAtario]

@@tullochgorum6323 "Exotically complex sharded distributed setup"s come off the shelf from cloud providers and have for quite some time now. But it is indeed true that bankers prefer to throw money at problems

[@rottenanimal619]

I worked in tech all my life (now retired) I have a computer hard drive almost 3.5 feet in diameter. It was hanging on the wall as a decoration, at a company I worked for, almost 35 years ago. At that time the company was doing a major cleanup and it was headed to the garbage. I asked if I could have it and I still have it today. If you want. I will send a picture.

[@maxxomega6599]

People have been saying "Mainframes are dying" for 40 years now. I don't believe it will ever happen. I loved working on them, all flavors of OS. MVS, MVS/XA, MVS/ESA, Z/OS, etc, etc. Working with TSO, ISPF, JES2, CICS, ACF2, RACF, ESP, CA7, IDMS, IMS, JCL, etc, etc. I did everything from System Operator to Systems Programmer. I'm retired now, but it was an awesome career, working on Y2K was a blast.....One awesome thing about Mainframes was how you could have one running CICS and people from Alaska to the tip of Florida could all get the same sub second response when hitting enter...very fast...

[@toadjam12000]

Sounds like you worked at EDS.

[@RegularCupOfJoe]

I'm about 6 months late to this comment, but I was in the crowd saying, "mainframes will die because of cloud computing." Then I worked for a university, several insurance companies, even a court system... all of which shut my mouth up about mainframes going the way of the dodo. There is an elegance and grace to mainframes that commodity systems simply cannot come even close to.

[@jetblast1212]

Facinating Dave, you have a knack for explaining amazing and complex things into understandable infotainment. Keep up the good work.

[@laurenmp7486]

This is so awesome to see! I's nice to see the people who make them, still want to make them and keep trying to make them better.

[@MichaelEhling]

Yay! That was fun! Can you do a follow-up episode on Z16 system software? I bet that's just as interesting as the metal (and glass and water and silicon and...)

[@ericsoul64]

Such a great and thoughtful overview. I hadn’t thought about mainframes in years, and now I get it. The uptime and local performance is unmatched. Thanks Dave!

[@hypercube33]

I know the AS/400 family used to be based out of Rochester MN (I dont believe it is anymore) and they allowed things like paying for cores after you've purchased the hardware (they were software locked and shipped basically the highest configuration CPU wise at least irrc) Edit: one of my favorite war stories was that a company had an IBM mainframe running in their server room and a semi ran into the building and pushed the whole mainframe rack across the room. IBM techs came out and made sure all the cables were still connected and it continued running until they were able to ship a replacement system out.

[@johnvriezen4696]

The manufacturing is no longer in Rochester, but much of the os and integrated db software is still there .

[@csukosd]

This was awesome! More Dave field trips need to happen.

[@dale116dot7]

The construction of these machines is quite impressive. It’s interesting to see related processors crunching so much data. I work mostly with the Power architecture, but the small version of it - a three-core e200z4 with a eTPU timing coprocessor. The heatsinking here is very impressive! In my world (automotive ECU design) we run them at 150MHz to keep the power dissipation down.

[@andreichichak5242]

Shhhh, don't tell people that their cars are likely running small versions of these CPUs. Well actually the eTPU is running their engine, the CPU is just watching and adjusting.

[@Cuplex1]

Interesting video, I do appreciate the varied content! With all the focus on NVIDIAs supercomputers, it was interesting to learn about what IBM focuses on and how they differ.

[@ETRdotTV-i1b]

So cool. I worked as an operator in the Toronto Computing Centre at 245 Consumers Rd from 1975-81. I started on the S360/65 and /75 and I do remember virtualized S370/158VM systems that were on the floor by the late '70s, although I went the S370/168 route with its MVS/Jes3. Phew, can't believe I remember those model numbers!

[@clifforddicarlo9178]

Super presentation, Dave. Next, Discuss the operating system [ZOs?] tying/managing all that hardware together.

[@DaveEtchells]

Wow, I love seeing engineering on this level! I was wondering and then you gave us the stat: *seven* 9’s reliability? That’s just insane!

[@oneeyedphotographer]

I remember Microsoft claiming five nines. I made my reasoned rebuttal to the Trade Practices COmmission (Australia). The TPC accepted the MS explanation, but those ads ceased. My rebuttal was simple, take away minimal maintenance time for Windows (NT), there just wasn't enough time left. It's not better with Windows 11. Linux, I reboot to change kernels. Everything else I upgrade, but choose whether to restart, individually.

[@billklement2492]

Dave, cool video! I remember reading that financial tractions would be processed by 3 mainframes in lockstep with comparators on the input and output. That would catch errors made by one mainframe and use the output from the agreeing 2, flagging the error. If all 3 disagree, it would halt the system. You could take one mainframe down and not lose redundancy. Thanks for the video!

[@indisputablefacts8507]

I worked a semester at IBM RTP in '85, working on a PC app. All our developer builds were performed by a 3090 (mainframe) in the basement. Compared to compiling on the PC, it was wicked fast. Since then, I worked at a bunch of places. Only one of them had a better developer-build solution than what I had back in '85... and that place definitely wasn't Microsoft.

[@squirreldriver]

When 'eventually consistent' just isn't an option, in other words? Commodity hardware and increasingly sophisticated distributed transactions, parallelism, etc. is capable of addressing some traditional mainframe workloads, but instantaneous distributed commit at seven nines of availability? Some problems still have to be solved absolutely from the iron up, and you have made me realize how happy I am that IBM is still on the job!

[@timneal517]

Recently discovered this channel. Love it. Particularly enjoyed this episode on the IBM Z. I would love you see you do something on LinuxOne. :-)

[@DavesGarage]

Great suggestion! Planning on it!

[@Doesntcompute2k]

Dave's Excellent Video Production Services strikes again! Dave, amazing video! I'd (almost) PAY for that video loop of the drive up there with the changing leaves! As someone at a very large multinational company with IBM mainframes, and soon to have the Z16s to replace the 15s, I can say how cool, sexy, and awesome they are. Z16s are far, far, far past any mainframes we had in the 80's and 90's. I do run mainframe code at home on my "homemade mainframe," ( LOL ) but it's not the same of course. Although I only need 300W of power on my Dell PowerEdge T320 to run VM/CMS and MVS/370. Please THANK IBM for allowing you such access to their new toy. I'd love a view inside there myself. But I geek out on stuff. Oh and congratulations on marrying your "childhood sweetheart" and still being together. As guys in our generation, it's rare, but so very awesome.

[@KameraShy]

I run my MVS system on a Raspberry Pi. Yes, you can do that and it does work.

[@donzoomik]

Your memory calculation for memory bandwith (for Xeon or any other x86 with 3200MT DDR4) is ~25GB/s per single channel. Most desktop CPUs are dual-channel, however modern Xeons are 8-channel and AMD Epycs are 12-channel, with DDR5 (4800MT/s) so depending on system you could be talking (Xeon DDR4 3200MT 6-channel) 150GB/s up to (AMD Epyc DDR5 4800MT 12-channel) 450GB/s per socket.

[@phizc]

Yup, came to say the same myself.

[@ProcessedDigitally]

he knows. its just to invite comments..

[@willd0g]

ELI5

[@gt2847c]

The one thing IBM needs to do, but has always been vehemently reluctant to do is provide a hobbyist version of zOS... Eventually they're going to run out of people that have the knowledge of how to run these machines. One of the reasons that OpenVMS still exists is due to DEC and those who bought them maintaining the hobbyists that became employees running those systems. Hercules can run zOS (or at least the older versions of it), and I imagine there would be a significant number of fellow geeks that would enjoy being able to learn on it.

[@markpeterson5479]

@gt2847c - Long ago, I thought about a hobbyist version of VM/CMS but what programs would I run on it? Same question about zOS. These operating systems are not designed for games or other programs that are typically run on PCs. . Also, I am sure that these operating systems are HEAVILY optimized for the IBM hardware and this hardware is RADICALLY different from a PC. It would be like the difference between a motor cycle with four-speed left-foot shifting and a semi which has a shift lever with two auxiliary thumb controls (a five-speed main transmission with two high-low auxiliary transmissions, giving 13 speeds). I think that it would take a huge effort to get zOS to run on a PC (or some other hardware that a hobbyist could afford to buy.

[@KameraShy]

Free versions of MVS and VM/CMS are out there. zOS is just MVS with Linux. I run my implementation on a Raspberry Pi.

[@zf4hp24]

@@KameraShy Isn't public domain MVS stuck at 3.7, which is 24-bit only? Ditto with VM?

[@shaynestephens]

Great video Dave!!! I lived in Cold Spring, NY, 18 miles south of Poughkeepsie. My older brother worked at IBM in Poughkeepsie and East Fishkill, NY and retired from there. My father worked there part-time for a few years. A few families in Cold Spring worked at the IBM complexes in Poughkeepsie and East Fishkill.

[@johnlozauskas778]

Great video. This is why you buy IBM and not Lenovo. In the 90's you wanted a ThinkPad because if you dropped it or it got ran over, chances are it would bootup, even with missing parts of the screen. The company I work for went from Dell to HP, common, but now are going to Lenovo and no one one wants to look at the fail rate. Until a big wig has their laptop not boot up after a week, then it's a crisis. I learned things about Mainframes I did not know. RAIN (redundant/reliable array of inexpensive/independent nodes). Make sense, like pour water into places on a field where there is space for it. I've never worked with one directly, but my parents did back in before the day in the 60's, 70's, and 80's when 64k of RAM was considered massive and they used punch cards. The biggest innovation to punch cards was to number them, game changer.