The Forbidden and Forgotten UMC Green 486 CPU

[@erinwiebe7026]

In the mid 90's, I worked at a small, local (also Canadian) computer shop. It was one of my first jobs out of high school, and well before my IT career. I helped do all kinds of jobs there, including building made to order clone PC's. It was the mid 486 era, and we sold mostly Intel & AMD 486's. The shop owner showed up with a UMC 486 33 one day and at the time it was considered an oddity and it ended up sitting on the shelf for months before we finally decided to build a system around it. Seeing it run, I remember being rather surprised how well it benchmarked, and I wondered why we didn't see more of these CPU's making their way into new builds. It was the first and only UMC 486 CPU I ever encountered in person and your video brought back some fond memories of working at that little computer shop. Thanks!

[@vswitchzero]

Thanks very much and thanks for sharing! Always love to hear these kinds of stories from back in the 90s 👍

[@wowitsshit9734]

Ywnbaw

[@АндрейМилованов-у9у]

similar biography, but w/o GREEN CPU, few years before (begining of 90s) and in Russia

[@idahofur]

I remember the name but, I don't think the shop I worked for sold any.

[@dumiicris2694]

benchmarked back then? and i had 80 mhz amd so i so what it can do.. u have 12 16 33 .. 120 mhz what benchmarked? unbelievable.. first cpus 1 transistor and 1 resistor benchmarked? im speechless i can not beleve this sorry benchmarked because of faster ram or nice video card .. can not beleve this sorry .. a cpu that needs fast routines to make some graphics fast enough .. thank god i never seen benchmark back then..machine code everything if u want for things to move normal and yeah everything was a pain in the butt benchmarked!! :))))

[@the_beefy1986]

I love the use of Gameboy cart cases to store CPUs

[@tetsi0815]

I wonder where all the game cartridges are...

[@Sarge92]

@@tetsi0815 you can buy those brand new empty

[@bubu5908]

@@tetsi0815 In In the CPU packaging, of course.

[@rolux4853]

Yes! All my old CPUs are in a drawer with some dividers to separate them. Now I feel guilty that they slide around if you open and close that drawer a bit more quickly.

[@robertsmith2956]

I keep all mine in the box they came in when I bought them. Takes up a lot more room that way.

[@ugzz]

I remember "Zipping" Quake 1 onto about 15 floppies with max compression and a 1.4mb split. Backpacking that to a friends across town. All 15 floppies worked, recombining the zip worked. Fully extracted no problem.. We were SOOO geeked!.. Then we learned about FPUs.. No quake on a SX 486.. Such disappointment!

[@mirkoslavko3703]

There was a FPU Emulator, it worked well on my 486sx25@33 MHz.

[@John_Smith100]

Similar story splitting game demo downloads at school and taking them home across multiple floppies, then figuring out which split had failed CRC check. Got caught once hiding the download window behind a fake picture of a bare desktop.

[@ugzz]

​@@mirkoslavko3703 Whaaaa?? (mind blown!)

[@shelterbloodfallen8851]

Or Duke Nukem 3D, Transfer with Floppys. Ready to start Multiplay with Modem (No Internet, direct to a friend. Late afternoon).... oha Mainboard has a ... 8000er Serial RS232 Manage Chip. Makes the game unsyncing .... damm fast , i buyed a new Mainboard only for that game 🙂 Hahaha.... payback time!!!

[@jimbotron70]

​@@mirkoslavko3703No way working well for such a demanding game.

[@georgeh6856]

I am glad you said you are Canadian. When I saw that "NOT FOR U.S. SALE" label, I was about to call the CPU police.

[@vswitchzero]

😂

[@cryptocsguy9282]

😂😂😂😂 I think the CPU police is the US government nowadays

[@tcpnetworks]

I used a UMC U5S in an embedded machine back in the mid-1990's. It was in charge of producing glass bottles at a production facility - in charge of 14 stampers and 2 furnaces, it kept everything working nicely.

[@geografiainfinitului]

That UMC logo looks something straight out of Robocop

[@bleeedthebrakes]

At least UMC did learn from this and spawned into all other architectures that intel hadn't had their hands on. Mediatek, Novatek, JMicron, ITE, SiS, Faraday are all part of the UMC franchise.

[@SianaGearz]

Huh. SiS chipsets had the fastest memory controllers for a while, and were actually sort of robust and not too buggy.

[@MrBooMY3]

My first personal experience with over clocking was the main seller at our old computer shop. It was the AMD DX4-133 I had setup for a customer. I accidentally set the bus speed to 40mhz and saw the 160mhz on the screen as it counted RAM and booted up. I was like 160 oops but i have to benchmark it and see is it stable. I ran that one with the flying pc and keypad and it smoked any score I'd ever seen come from my shop including the previous record holder which I think was a P75. It was perfectly stable in anything I played which included Doom of course. When we told him he got a free over clocking upgrade he was like sweet. We sold a bunch of them because it was significantly cheaper than the Pentium but performed just as well in most things at the 160mhz clock. I always tried 50mhz but never got one to run reliably at that speed even with extra fans cut from old power supplies.

[@glitchwrks]

Neat! I'd seen the UMC CPUs mentioned in motherboard jumper tables but never actually saw one in the wild.

[@udirt]

Same, I only remember that blue lighting ibm cpu as Enigma 3rd party cpu that was notably fast. Would have been cool to have had one of those!

[@Rouxenator]

I remember these, they were pretty common here in South Africa. My cousin has the SX40

[@Fusso]

Brazilian here. Had one those around 1995. It was pretty common. What I never saw was an original Intel one.

[@ville_syrjala]

I see no source for that 7 cycle integer division claim in wikipedia. Would be cool to actually test that. The "AGP" model of the Millennium II is in fact just a PCI device, and AGP runs at 66MHz, so it's possible that most Millennium II's can handle that frequency just fine, unless Matrox had to use special binned chips for the AGP cards.

[@udirt]

IIRC the et6100 etc were also quite overclock friendly

[@PiDsPagePrototypes]

Those things were so hard to get a hold of when brand new, then they were a pain to set up, and then suddenly they were everywhere, being tossed out with the Dell and HP business workstations they were standard fit in. The long sockets on their side were for the Video Graphics Overlay board that used software for doing Lower Thirds and the like in TV stations.

[@SianaGearz]

AGP will gracefully degrade to older PCI standards if need be, so a card doesn't need to support 66MHz.

[@HappyBeezerStudios]

@@SianaGearz A bit like with the Voodoo cards, which never made use of all the fancy AGP features.

[@intrinia]

And I thought I have seen every 486 manufactor. Great video!

[@vswitchzero]

Thanks very much! 🙂

[@HappyBeezerStudios]

Look at the Texas Instruments and ST Microelectronics 486

[@intrinia]

@@HappyBeezerStudios Have some of them laying around. ;-)

[@Zerbey]

Never heard of this before, but yeah I'm blown away by those benchmarks. Wish I'd known about these in the 1990s!

[@the_kombinator]

0:05 - I thought I was very much the only one storing 486/Pentium CPUs EXACTLY THAT WAY lol.

[@luke5957]

Wow where has this channel been, subbed

[@vswitchzero]

Thanks very much for watching! :)

[@ahu747]

Bro i grrw up tinkering with 486dx 50s, dx2 66s, then a pentium 133. All your videos bring back so much memories

[@josephalbrecht3735]

Thanks for a very informative and interesting video. I just picked up 486 VLB system with a PC Chips M912 v1.7 motherboard. I purchased UMC 486 Super40 that I will be using in this system. I never used one the CPUs back in the 90s and now it is going to be a lot fun to try this out!

[@vswitchzero]

Thanks for watching! Very nice, enjoy the new retro system 🙂👍

[@josephalbrecht3735]

@@vswitchzero I got the UMC 486 CPU today and it works just fine in the PC Chips M912 v1.7 motherboard. This motherboard has specific jumper settings for the UMC 486 CPU. Interestly, those jumper settings differ from a standard Intel 486SX.

[@djlim4612]

I miss Cyrix. Used their 6X86 up to MII. Thanks to them, my family could afford to buy PCs for me and my siblings. Thanks for the video..I really haven't heard of UMC processors. Winchips, Cyrix , Nexgens ..wish they are still around.

[@JeremyLevi]

Same. I had both a Cyrix 5x86-100GP and later a M2 6x86MX-PR200 (150Mhz). The 586 was a bit of a stinker but the price was right and was still a big upgrade from my previous AMD 486DX40. The M2 was a great chip, ran flawlessly at a 75MHz bus x2 clock multiplier for years.

[@paulmcgrath2175]

I also had 150Mhz 6x86, mine had ibm markings, as they made the chips for cyrix.

[@djlim4612]

@@JeremyLevi Awesome. Mine was a 6x86 P-166+. And then the M2-333 came along. (My brother bought a Via Cyrix III thereafter but sadly i've never gotten to use it). All 3 were relatively slow in gaming but it was affordable and lower the bars of many families to owning a PC. Team Red all the way after the sad demise of Cyrix. Now my Cyrix 6x86 cpu is on display next to my Ryzen PC. Beautiful golden chip.

[@HappyBeezerStudios]

They sort of still are around. Cyrix sold the division to VIA which are still around and still make x86 chips. Cyrix MediaGX went to become AMD Geode NexGen were taken over by AMD and their RISC86 design powers the K5 WinChip were made by Centaur, then owned by IDT and later sold to VIA, where they made the C3and the succeeding designs, including the recent Zhaoxin stuff. And UMC are also still around and one of the biggest semiconductor producers worldwide.

[@djlim4612]

@@HappyBeezerStudios Agreed. But what i meant for them to be "around" is for them to still sell CPUs on the market to average joes, like AMD & Intel. Would be bloody awesome to have a battle between AMD Ryzen 7800x3d, Intel 14900K (if they don't explode beforehand) and "Cyrix CX 9000" yeah :D

[@briangoldberg4439]

Intel probably saw them as a real threat with those performance numbers. I mean, in productivity software, you wouldn't really need to upgrade to a Pentium until Windows 95 came out

[@effexon]

ah good old block dealerships to take competition by shady threats.

[@Telecasterland]

Am5x86 133 overclocked to 160 was the king of the hill of the 486 boards.

[@lynnjr457]

Even though they tended to overheat during long production usage. I worked for a company that decided instead of going to legitimate pentiums, we would deploy those overclock cpus. Until we figured out the overheating issue, we had months of machines hanging up randomly. Eventually we modified some 1U appliance fans with much higher RPMs that kept the CPUs cool.

[@Lalasoth]

@@lynnjr457 I had one of those but never had that issue. Was awesome for its time. When I would tell people about it I usually received nothing but disbelief.

[@epickh64]

486's are my favorite CPUs of all time (closely followed by the MOS 6502). I love to see videos about them. ^^

[@IronwingTechHaven]

This is so cool! I've never even heard of it. Awesome video. I especially loved the overclocking section.

[@WalrusFPGA]

Impressive numbers and OC capability from this little known chip! Loved the overview here. Thanks for sharing

[@vswitchzero]

Thanks very much! 🙂👍

[@kasimirdenhertog3516]

Great stuff, subscribed! I had seen this chip featured by other KZbinrs, but you add some interesting details to the story.

[@vswitchzero]

Thanks very much! 🙂👍

[@repatch43]

Is it crazy that I still care about benchmark results for 486 class CPUs? No, not crazy at all. Great video!

[@vswitchzero]

Haha thanks very much! 😁👍

[@RetroTinkerer]

That is one cool rare CPU thanks for sharing!

[@retroboby007]

I have a motherboard with UMC chipsets, but I didnt knew they made CPUs. Very interesting stuff. And you have a cool testing system too. I saw your 486 dx2 66mhz reaching 49 score in 3d Bench. Very nice! My 486 dx2 66mhz never gets pasted 45 score in 3d Bench, even with VLB or PCI video card.

[@HappyBeezerStudios]

Time to tweak stuff. And check things like fastvid and mtrrlfbe

[@makingtechsense126]

What a trip down memory lane. In the early 90's my parents decided to buy a computer for the entire family to use. It had an Intel 486/SX-16 in it. Needless to say, it wasn't great. At some point we upgraded to an IBM 486DX2-66. I have never heard of the UMC Green 486 so thank you for sharing! Seems like UMC had a very talented engineering team. Too bad Intel killed off their CPU business.

[@ryanyoder7573]

There is no 486 SX 16. The 25 was the lowest clock speed 486 SX.

[@ryanyoder7573]

Hah. I checked Wikipedia and I was wrong. I built hundreds of computers back then but literally never saw a SX 16 or 20.

[@makingtechsense126]

​@@ryanyoder7573- No worries. I had to double check my memory too. Obviously it was an outlier.

[@vswitchzero]

They are actually quite difficult to find these days! Would love to find an SX-16 one of these days. They were typically only used in OEM machines. I believe the 16s were exclusively found in some Dell models.

[@aemerox5773]

You just answered a question that I was looking for for almost a decade. I remember talking about it a long time ago to KZbinr who went by the name WayBackTech and had made a review on UMC Green. I asked if this CPU was forbidden to be sold in the US, this doesn't include the rest of North America. This meant Canada and possibly Mexico could get their hands on one. Well that question was finally answered.

[@Phantomwiz1985]

Bloody rippa of a video mate. Just awesome. Good stuff

[@vswitchzero]

Thanks very much! 😁👍

[@ElNeroDiablo]

YT randomly rec'd this vid to me, was an interesting watch about a piece of PC tech history.

[@vswitchzero]

Thanks for watching! 🙂👍

[@ninja011]

I used to have a system with a U5D in it. It was a custom tower built by a system integrator in Montreal when I lived there. I used it for school work and later upgraded it to a Pentium OverDrive socket-compatible CPU.

[@tngaskell]

Thanks for making this video! I was just thinking about the Green earlier this week but have, of course, never seen one in person.

[@ToTheGAMES]

Keeping CPU's in Gameboy cases is a smart idea! I'm gonna do that too, thanks!

[@emlyndewar]

I don't know why this was recommended to me, but I'm glad it was!

[@vswitchzero]

Thanks very much for watching! 🙂👍

[@MarcoGPUtuber]

I picked up a few at the scrapyard. I think they're neat!

[@indiocolifa]

Wow!! I didnt know UMC 486 clones were so good. I remember them but In my mind they were in the same league as Cyrix or IBM SLC , great video

[@poseidon3032]

My dad bought me an AT IBM compatible mid tower that contained an AMD 386DX. When i got frustrated with trying to play Doom, found a computer shop in downtown of our city and upgraded the motherboard along with an AMD 486 DX2-80. Before the end of that era, I had outfitted it with an AMD 486 DX4-120. When later in 1999, I opted for a prebuilt eMachine with a Celeron 466 mhz, I gave it to a friend, much to my own chagrine. It ended up having 8 megs of memory, a WD 1.2 GB hard drive, a SCSI Plextor (I didn't research enough before I bought it) CD drive, Trident SuperVGA video card, Orchid sound card, and it ran Windows 95. I kick myself every day for not hanging onto it. I played Doom, Wolfenstein, Duke Nukem, Hexen, Xwing, Panzer General, and Myst on it. The Windows 95 disk even had the Rob Roy previev which i watched with fascination. The beginnings of what would later become the MPEG, WMV, QuickTime, and AVI video standards that we know of today.

[@Vanessaira-Retro]

Superb video! Great overview on this CPU.

[@vswitchzero]

Thanks so much! Glad you enjoyed it 👍

[@JeremyLevi]

Nice to see some performance tests for this rare bird and especially overclock performance. Now I'm curious how well it'd test out on a good VLB motherboard on those higher bus frequencies. I'd also be curious to see if there's any difference on your board with the jumpers set to standard Intel settings vs the UMC config just to see if there's maybe any chipset specific optimizations going on there to help out the UMC CPU performance.

[@vswitchzero]

Thanks for watching! I’ve never had much luck getting VLB to run stable at 50MHz, unfortunately. In my limited testing, I saw no difference between the UMC jumper settings and the Intel SX when it comes to performance. I wonder if it has something to do with the power features perhaps? Would like to look more into this at some point.

[@JeremyLevi]

@@vswitchzero That's a great point. It's certainly possible the UMC settings on the motherboard jumpers are related to the unique power saving features of the CPU.

[@SUCRA]

Great video. Amazing results for the Green CPU. If they did 3x multiplier version of it they would compete with the first pentiums. Very interesting!

[@vswitchzero]

Thanks, Bruno! 🙂👍

[@aleksandarsusnjar9574]

DX50 is for specialized systems and cases. Pair it with proper memory for memory-intensive processing or, with 50MHz-capable VLB video cards for it to shine.

[@envoycdx]

Do you mean use cases? Examples would be appreciated as I have a DX50 sat on the bench :)

[@JeremyLevi]

The trick was always finding VLB cards that ran stable at 50MHz. Maybe by now we know all the good ones but getting a stable config back in the day was a real case of trial and error. I knew more than one local beige-box PC retailers in those days that refused to build DX50-based systems for that exact reason, it just wasn't worth the support headaches.

[@mattelder1971]

@@JeremyLevi The DX2-66 was just all around better for most people. Lots of software just refused to run correctly on the DX50, even if the system was otherwise stable. However, I do recall one friend coming across one odd game (I can't recall what it was) that absolutely refused to run on ANY clock doubled chip, but worked perfectly on the DX50. It must have had some kind of timer or something that compared the bus speed and the clock speed and wouldn't run if they didn't match.

[@HappyBeezerStudios]

@@mattelder1971 makes me wonder what other processors that game can be forced to run with.

[@GarthBeagle]

Crazy, had no idea these were that good!

[@spladam3845]

Wow, that part is impressive, I wish I had access to these back in the day, I wonder how much they could be had for.

[@tech5882]

I built my BBS machine with UMC chip. It worked just fine while... it was cool. There was no a cooler designed specifically for the chip as far as I know. So I had to make my own cooling set up. Most of summer time case was wide open and had an additional desktop cooler blowing air into the case. :D

[@Ale.K7]

Great chip, great video!

[@kirkh4205]

(14:55) I have never seen a USB to IDE adapter like the one you're using. Does it also have nand flash memory on board? I see the USB Pen is not plugged in.

[@vswitchzero]

This is actually a "GoTek" floppy emulator. You can store many floppy images on a single USB stick and switch between them. Very handy to have with retro DOS systems!

[@TalesofWeirdStuff]

I always thought it would be fun to pair a UMC Green with a Weitek 4167. Rare CPU + ultra rare FPU = 😍

[@vswitchzero]

Haha would be very cool 😁 .. hoping one day I’ll find a Weitek 4167.

[@davidfernengel1825]

Excellent video, thank you! What an interesting CPU. It's a pity they could'nt continue selling CPUs.

[@vswitchzero]

Thanks for watching! 🙂👍

[@Bluecedor]

I remember that once I had convinced my parents to buy a quite expensive 486 DX2 66 in 1993, I soon started seeing the Pentium 60 and 66 hit the shelves. Then AFTER that, I started seeing DX3-75s, DX4-100s, and a dozen other permutations.

[@everTriumph]

I seem to remember a version of the 486 to fit the 386 pinout, so you could upgrade your 386 system to 486 by just swapping the cpu. May even have one in the bits box.

[@vswitchzero]

Indeed! There were a few but the most popular was probably the Cyrix DLC. Hoping to do a video on it some day 👍

[@ahabwolf7580]

Very cool, thank you!

[@KlopsKopp]

Love ur Gameboy Cartige Cases 😄

[@ausnorman8050]

Great Vid. I was just wondering on the 60Mhz OC, was unstable due to voltage or temp? Would putting anything on the ceramic top help dissipate the heat and make it 'more' stable?

[@vswitchzero]

I didn’t show it in the video but I had a decent sized heatsink and fan on the chip for all the overclocking tests. Cooling did help because the chip was always more stable when cool and would go down hill after running for 10 minutes or so. Would love to get a super-40 which is probably better binned. Thanks for watching! 👍

[@HappyBeezerStudios]

The 90s were so wild. Besides x86 with Intel, AMD, Cyrix, VIA, Texas Instruments, IBM themselves, UMC, ST, and a bunch more, there were also lots of other architectures still around. PowerPC, i960, Arm, 68k, SPARC Alpha, PA-RISC, AVR, SuperH, M32R

[@Fifury161]

I recall these CPUs and still have a few. As for the DX-50 I had to swap it out for a DX2-66 as the the motherboard couldn't support bus mastering when used with 2 VL SCSI cards and gave lots of r/w errors.

[@tapy5696]

It really was an amazing processor, when I first had the chance to test it I immediately ditched my Intel DX33. Its potential for overclocking resulted in the frequent addition of the designation by rogue vendors. I have a U5S-SUPER25-33 in my collection which was supposed to suggest its default operation at 33MHz.

[@MrEditor6000]

It's just amazing to even look at older chips, because it looks like you have a whole power plant under that lid.

[@rfmerrill]

It's so weird to be reminded that UMC has such a big presence and such "serious" products when they're also known as the biggest manufacturer of clone NES chips. Their NES CPU and PPU design are probably the most common ones to find besides Nintendo's own.

[@tiemanowo]

Watching your videos, I can imagine what channels like JayTwoCents or GamersNexus would look like if they were posted videos from the 90s.

[@vswitchzero]

Haha that comment really makes my day 😁 .. thanks so much 👍

[@bigwave_dave8468]

Early on when the 486 came out, there was no low-power model. For that reason, we used a Cyrix 386 with an outboard fpu for a portable compute solution.

[@boardernut]

there were never a Cyrix 386 on the market.

[@ThunderClawShocktrix]

@@boardernut He might be thinking of the SLC or DLC which had the pipeline and cache of 486 but ran in 386 socket

[@hwertz10]

I tried to get one of these back in the day, before I found out they were essentially not available in the US. After my 386sx16, I ended up first with an IBM 486SLC2 (which was horrible, it was actually a 386 made compatible with a 486 socket, including the 386's 16MB RAM limit .) It was fine at first, but I ended up with this stuipd thing in a VESA Local Bus motherboard, only to find the video memory was mapped past 16MB -- it did some wraparound thing with the memory so the VRAM was mapped at like 8MB or so. When I had 8MB RAM it worked. When I bumped it up to 16MB, all hell broke loose since the VRAM and some of the system RAM's address spaces overlapped.) I went AMD after that -- K5, K6, K6-2. All served me well.

[@Fortunes.Fool.]

We had a Dell 386/25 and a friend’s dad had a Gateway 486/66. I was blown away how fast that was when we installed games on it. Seeing a Cyrix chip brought back 90s memories, so cool.

[@lemagreengreen]

Just a little thing but that Intel DX4 in the opening shot with the logo off-centre is interesting, never seen one like that before. Assume it isn't a mis-print but it sure looks like it!

[@vswitchzero]

Indeed! It’s an oddity for sure. I got that one out of an industrial system a few years back. Never seen another like it 🙂

[@IBM_Museum]

The Intel S-spec 'SX911' (486DX2-66) shown during the intro is great for a baseline of the last Intel DX2 with the standard 8Kb Write-Through L1 cache - You need to get the 'SX955' S-spec for a comparison of any speed boost for Write-Back L1 as compared to Write-Through. That test is made slightly more easily at the Intel 486DX4 level since there are more batches to 16Kb L1 in WB or WT. Another note that the POD63/POD83 can be really nutty with L2 cache (typically 128 or 256Kb if present) on the motherboard.

[@HappyBeezerStudios]

Yeah, it comes pretty close to the 35 fps for doom, and that was recomended on a DX2-66

[@vswitchzero]

Thanks for your comment! I’ve been keeping an eye out for an SX955 and the DX/50 SX954. Would love to try them out. I do have an &EW DX4 with 16KB WB L1. Interesting that you mention that the POD can have issues with L2 cache. I was always surprised that the cache latency benchmarks were pretty poor with the POD. Thanks for watching 🙂👍

[@YarisTex]

All of us should spam UMC like crazy for them to do a production run of these 486’s on a more advanced node. 1GHz UMC 486

[@yournamehere23435]

I'd be interesting to see how fast a 486 could be just for the fun of it

[@virtualtools_3021]

​@@yournamehere23435especially wince just 6 days ago someone finally modded xp to work on 486

[@briangoldberg4439]

lol. what would you run on it?

[@jbaroli]

What bus frequency it would run? On which motherboard?

[@RuSrsbro]

​​@@jbaroliThey would have to engineer a way for the chip to run asynchronous to the bus speed, anything above 100 MHz is just not feasible

[@Turktien]

Great vid!

[@HappyBeezerStudios]

Would be interesting to see more niche CPUs. Stuff like the Transmeta chips and how usable C3 and C7 were compared to their direct competitors.

[@kultur-vultur]

Hey I like the use of GB cart cases to hold CPU's, gonna have to use a few myself now.

[@unclemusclez]

really cool stuff

[@jermz79]

I remember seeing an ad for a 60mhz CPU at Fry's Electronics on the back page of a newspaper and thought they probably mixed up CPU speed and hard drive capacity.

[@xrysf03]

I recall booting Linux on a miniature embedded x86 motherboard, where the CPU would identify itself as UMC. Must've been during the noughties. Not sure if this could be an early VIA/SiS, rather I'm inclined to believe that this was something of the DM&P pedigree, i.e. and early Vortex86, a direct predecessor to Vortex86SX. Could it be that the modern Vortex chips inherit some history from the UMC 486 ? Perhaps by now there have been too many generations for any heritage to even matter, at the level of CPU core design... And yes the modern Vortex CPU's do feel like a very fast yet very lean 486DX+ (with CMPXCHG added). I believe around Vortex86DX the CPU was claimed to be "fully static", i.e. you could stop the clock for an indefinite time interval, and restart it and all the code would keep ticking (no data would get lost) - and it could be deeply underclocked, if you had to run stupid software that would not tolerate a CPU that's just too fast. Like down to 1/8th or even 1/16th. (A feature of the platform, accessible programmatically via some chipset registers, also available in the BIOS Setup on the motherboards by ICOP.)

[@NaoPb]

But will it run the Windows XP that's been modded for 486 cpu's?

[@vswitchzero]

Would be really interesting to try! 🙂

[@jbaroli]

I had no clue that there is a WinXP version modded for 486

[@andrasszabo7386]

Where can I find XP for 486?

[@doq]

The vendor string is "UMC UMC UMC " because the vendor string is 12 characters long and that pads it out perfectly. VIA Technologies had their vendor strings as "VIA VIA VIA " for the same reason.

[@wpyoga]

And they wouldn't repeat their name 4 times because the number 4 is perceived to be bad luck by the Chinese.

[@a120068020]

I love the 486 collection!

[@tinkmarshino]

I still have my 286 and my 486 with a cd player.. I must get these operational sometime just for kicks.. and see what I have on them?

[@testingchannel5440]

Unrelated question: where can I purchase the plastic cases you used to store the processors?

[@vswitchzero]

These are actually aftermarket GameBoy cartridge cases. I bought some 10-packs on Amazon and they are perfect for most retro CPUs 👍

[@HTMLEXP]

That stability in an under-voltage scenario would have made the UMC.486s great for laptops of the time I would have thought.

[@nazgulsenpai]

Using those GameBoy cartridge cases for CPUs is genius :o

[@XVa-uj8m]

I would love you to get that engineering sample too as any chance you could make an ao486 Core for the MiSTeR based on that? It would be so awesome.

[@vswitchzero]

Hopefully one day I’ll find one! Would really be awesome to see this turned into a MiSTer core 😁

[@revcrussell]

Still working on building my all-UMC machine: chipset, processor, SRAM, VGA, super I/O

[@mwk1]

UMC z perspektywy Pegasusa - Szanuję! 😎

[@wei48221]

The guy that worked on developing the UMC x86 CPU left UMC and started his own company call RDC which is still developing x86 compatible CPUs and SOCs today.

[@SickanFilms-ym3lj]

I worked at a company back in the day where we imported components for the company's computer brand from Taiwan. We used UMC Green for the low price range. I remember it had some small issue with a certain software but made a very good computer for the price. I even visited the factory in Taiwan once.

[@vswitchzero]

Thanks for sharing! 👍

[@javabeanz8549]

Okay, after watching all of this do you happen to have the Intel 486 100 MHz overdrive chip, looks almost identical to the POD in the video. And do you have any of the AMD X5-133 chips?

[@vswitchzero]

I do indeed. Both of those chips have 16KB of write-back L1 cache and would be a bit faster clock-for-clock compared to the older Intel/amd 8KB models. Not nearly enough to catch up to the UMC green though 🙂 .. I did a few videos in the past on these chips, including an upgrade chip comparison if you’re interested. Thanks for watching!

[@javabeanz8549]

@@vswitchzero The biggest problem that I remember from those days, was motherboards with fake cache chips on them. I was working in a computer store at that time, and we had to return an entire case of them. I had build a system, but it didn't feel right, so we started looking into more details, and found that the chips were just glued on the board, no actual solder. I also really enjoyed the AMD K5 CPUs, blazingly fast and cheap compared to what we were used to from the 486 systems and the early Pentiums that you could use to cook with.

[@jonathanellis6097]

Intel.... stifling innovation since forever, the CPU market would be in a better place by now probably if UMC had carried on as a serious competitor. Intel were clearly scared.

[@benchang888]

Now UMC is making android cell phone CPUs competing with Qualcomm.

[@ig8___]

I bought this when Starcraft released, upgrading from 66mhz to 120mhz - getting past the pentium 75hz required for Starcraft. Also 1st processor upgrade for me

[@paulmcgrath2175]

I still have my dx50 cpu. It was the first pc I bought new and cost me $3500.

[@Mr_Meowingtons]

Would have been sweet if they had came out with a dx2 or a dx4

[@HappyBeezerStudios]

They worked on a DX2, but it never went past engineering samples.

[@mattelder1971]

I was in the Navy stationed in Asia at the time and I seem to recall seeing these processors. If I had known how good they were, I would have bought one back then.

[@AtomicOverdrive]

I had an AMD 486 DX2 66 that I overclocked to 100mhz by dropping the buss to 25 and putting the clock to 4x. Ran rock stable and paired with the 16MB of RAM it was a dream machine for me in HIghschool.

[@vanderlinde4you]

Likely even slower considering the dropped down bus.

[@AtomicOverdrive]

@@vanderlinde4you Nah from 33Mhz buss to 25Mhz wasnt massive. Noticable if you only had a 33Mhz and went to 25Mhz, but since I went from 2x to 4x on the clock multiplier, the overall net performance was quiet good compared to it at just 66Mhz. Didnt have any bench test, but just running programs in general, it was very noticable improvment and programming compile times where WAY WAY faster.

[@vanderlinde4you]

@@AtomicOverdrive fsb wins over clockspeed.

[@AtomicOverdrive]

@@vanderlinde4you In many cases yes, but a full 34 more Mhz overall was more of an improvement in this case. Anyway, what ever you claim, it was my PC and I tested the results from the OC and it was an improvement across the board.

[@ferencszabo3504]

When they shared the same socket type, those were the good times!

[@tellyjoossens4186]

I have the same Shuttle board (but in another color). Have an Am5x86-133 in it. By far the fastest 486 board I've ever owned and indeed very versatile. Bought it originaly with a 486sx. Man that was slow, even with the PCI s3 vga card at that time. Nowadays, I do my dos retrogaming on an Asus P2l97 board with a pII-333mhz cpu though. Slow/fast enough and the Gforce2mx-400 runs everything from Wolenstein 3D to Quake to... without any hassle.

[@ted_van_loon]

if those cpu's had taken off then what would the impact have been on the future computer market. since the IPC was basically almost 6 times better, and the overall powerusage was much lower while overclockability and undervoltability where much better. that said I once had a AMD Phenom II X, don't remember which one exactly, but was one of the better one. it was passively air cooled so just a heat sink on it, but no fan on the heatsink(even though the pc case fan did blow over it), I had overclocked it with more than 1ghz extra(which back then was a lot since back then clock speeds where much lower. the cpu temperature at full load would get to around 30 degrees celcius, and in warm days perhaps more close to 40 degrees, but it stayed cool. it was stable at that 1gh overclock(despite the motherboard not even being stable at stock settings. I didn't dare to push it much further however since the motherboard was really crappy and had capacitor problems so I was afraid that pushing it much further would destroy the motherboard.

[@TheThorns]

I love the use of Gameboy cases for CPU's , LOL 😂

[@rootbeer666]

I'd be curious about a for clock comparison with 5x86 from AMD.

[@vswitchzero]

Thanks for watching! The Am5x86 has 16KB of write-back L1, so performance would be a bit better than the 8KB Intel/AMDs clock-for-clock. Wouldn’t be enough to close the gap with the UMC green though. Unfortunately I can’t run a 5x86 or DX4 at a 1x multiplier for a fair comparison.

[@sanitarium017]

Where did you put all your Gameboy games?

[@vswitchzero]

Haha wish I still had an original Gameboy, but the cases are perfect for storing CPUs. They are not originals, I buy these cheap aftermarket ones on Amazon in packs of ten for this purpose :)

[@dalant979]

great idea to test against the Pentium OverDrive with the fan disconnected!

[@technik87]

Yep, I still have this UMC Green PLC ;-)

[@Sparrow-bi6xh]

If you want real 486 speed use the AMD DX4-120. I had it running at 150 (3x50). It was a 3V part, but I ran it at about 4.2V (my board had 3 jumpers for 3V or 5V the power actually went thru so I used 5V thru a 3A diode )