RAM Explained: Ranks and Bank Groups (Why Dual Rank is faster)

[@vinney3472]

The two ranks are selected one at a time through a chip select signal, therefore only one rank is accessible at a time.

[@h1tzzYT]

Yep and to further explain memory interleaving, while it can access only single bank at a time, the other bank can refresh its data cells in the background, thus increasing memory bandwidth and reducing latency. Where's with single rank configuration, the cpu has to wait for memory bank group to refresh before sending another burst of data. Thats why memory interleaving is much more important for systems running stock or relatively slow XMP profiles. Once you manually tune your ram timings your single rank configuration does reduce the performance gap between dual and single rank configurations, especially that you may get higher overclock on single rank memory. Still, dual rank memory in vast majority of cases will always be faster than single rank configuration.

[@Crossfire2003]

Great video. I always go with dual rank, dual channel RAM kits.

[@vladislavkaras491]

Well, if you have single rank, you could use multiple single ranks in order to achieve dual rank. Like 4x single rank is like having 2 dual rank RAMs, and as I have heard, having more than 2 dual ranks does not really give you the performance. Also, looking at different benchmarks, mostly the difference is pretty negligible. Speaking about SO-DIMMs (laptop RAM), dual rank actually consumes more watts. I can guess the same situation with more RAM banks as well. Thanks for such detailed video!

[@nomoredamnnamestouse]

Having more ranks is better if everything is kept equal. but they present a higher electrical load to the memory controller that can potentially drive down clocks and timings versus less ranks. Electrical loading on 4 DIMMs also becomes worse on most mobos using daisy chain DIMM topology where one DIMM on the same channel has a shorter traces than the other. (The longer pathed DIMM is always electrically better so mobo manuals always recommend to use the furthest DIMM slots of a channel first) So its not a free lunch.

[@willjohnsonjohnson]

I hate that the rank is not advertised. I also wish consumer boards supported RDIMMs. They put less stress on the memory controller. On X58/LGA1366, I was able to run triple channel quad rank ddr3 2133mhz, using two dual rank sticks per channel. Not bad for an early DDR3 platform. With dual rank single stick per channel, 2400Mhz was easy to do with oem puke green RDIMMs.

[@Serandi1987]

So right! So I got the 4 x 8GB G.Skill Ripjaws V 4000Mhz CL15 but I can only run them together at 3600Mhz CL14.

[@SpecialEDy]

​@@Serandi1987Some motherboard BIOS will let you unlock the channels and execute different timings. In that case you could put the more stable dimms on their own channel at a higher speed. Otherwise, raise the voltage to the RAM and get some airflow onto the chips. You can pick up aftermarket heatsinks or aim a fan at them. More voltage and cooler Temps will increase the stability for a higher clock and tighter timings.

[@Serandi1987]

@@SpecialEDy thanks 👍🏻 I've got now really nice DDR4 dimms and get the 4000MHz CL16-16-16-36

[@Crossfire2003]

Kingston Fury does mention the ranking specs of their kits on their website.

[@NVMDSTEvil]

Its unfortunate that nobody has done proper benchmarking to show the differences in performance. By proper I mean 4x1Rx8Gb/2x2Rx8Gb vs 4x 2Rx8Gb vs 4x1Rx16Gb vs 4x 2Rx16Gb

[@askjx]

what you're saying wouldnt matter. the dual rank rams are only userul if you're going for a single channel set up like 1×16gb

[@NVMDSTEvil]

@@askjx you have no idea what you are talking about.

[@sodiumvapor13]

Lots of useful info. Subbed!

[@KodinSun]

it is necessary that the memory must be written ''2R'' because the banks can be on both sides and it will not necessarily be a double-sided memory..

[@thomas1699]

My Acer Predator (i-7) has 2 G-Skill 16 GB (Dual Rank) so-dimms. My Aspire 5 (i-5) has 2 unequal so-dimms. 4 GB on the board and a Crucial 16 GB (Single Rank) so-dimm. They both perform well per the CPU. G-Skill infers that their 16 GB Dimms/So-dimms are Dual Rank. Time-Tec plainly states that their 8 and 16 GB RAM is or is not Dual Rank. Crucial carefully does NOT say that their 16 GB Dimms are Single Rank or Dual Rank. PNY sells a 16 GB so-dimm with modules on both sides. But they don't SAY that it is Dual Rank. It pays to read up a bit before you shop. Cheers!

[@TheOgi22]

What? R is rank x8 is about x8 chips or x8 liek 8 bit per chip? and what is banks? im total lost when you start banks in x16 Please, can you explain?

[@imrannazir5585]

Can i mix 2 different rank which have the same CL latency? Such as 1Rx16GB + 2Rx8GB ? Will it show performance issues?

[@KhristopherJeffBaduelSaturinas]

I get better FPS on games using dual rank rams than the single rank

[@matthewmiller6068]

Ended up here trying to figure out a computer that had some bizarre crashing issues with new RAM and I'm starting to wonder if its some kind of single/dual rank problem...but no clue how I would figure out. What I got at BestBuy doesn't say on the package and crashes (hard lockup) before I can get the system up to look at it tho all sticks pass memtest86+. And of course the OEM only leaves vague information about "DDR4 PC4-21300 2666MHz Non-ECC SODIMM up to 32GB" with no other actual specifications. I hate this...feels like I may have to just randomly buy a few hundred dollars worth of memory that I will probably have to return a bunch of in hopes of finding a permutation that might work.

[@b0ne91]

Dual Rank is harder to run and likely clocks lower when you're reaching the edge of IMC stability. Do you really think the benefits of Single Rank are outperformed?

[@ArmChairPlum]

Its probably fairly minimal on real world performance at stock but stability wise if you are over clocking - tougher. That being said, if you were to run 4 single rank dimms (fully populate the slots) then you may find it performs worse as electrically the signals travel further. versus a pair of dual rank dimms. I know in my case that I'm running 4 32GB DDR4 dimms on my 5950x so its max memory controller stress. (dual rank x 4) It is happily running though at the rated speed from the manufacturer of 3600MT - course a 400MT increase over the stock speed isn't a whole lot.

[@panipu]

Good video. I was so confused with my sticks (32GB DIMMs, Hynix c-die 16Gbit, Dual Rank). Went from 3200@16-19-19-38 to 4533@20-23-23-40 but tertiaries are so confusing. In theory the _dd timings shouldnt even do nothing when using only two dimms but it doesnt boot if I set them too low.

[@honahwikeepa2115]

Thank you. I finally got it. 👍

[@SalamaAhmed-pj3jv]

would you recommend to use single rank rams if someone is willing to fill the 4 slots? And would there be any issue using 4 rams dual rank with only the default XMP? And thank you for all this useful information.

[@zawyarnasir5776]

can we use a single rank memory system with dual rank memory system

[@TechPill_]

Can you make a video on xls ram vs xll ram diffrenciation

[@ntana11]

Hallo. What happens when you put SR sticks to all 4 dimm sockets and what happens when you put DR sticks to all of 4 dimm sockets? Also, is there a way to understand the memory topology of your motherboard if you are not sure about it? Thank you.

[@CmdrSoyo]

2xSR per channel = Dual Rank 2xDR per channel = Quad Rank (very heavy in the memory controller, will not oc well) Most boards are Daisy Chain these days if you are not sure you can look at the traces at the back of the board and see if they either go from one dimm slot to the next (daisy chain) or split between the slots and go to both (t topology)

[@MrNNikolas]

@@CmdrSoyo Hallo again. Thank you for your quick answer. I am new to hardware technology, but I am trying to understand how things works from experts like you. You are very helpfull. Thank you again. Greetings from Greece!!

[@ChrisKadaver]

Is it standard with single sided 16gb DDR4 dimms these days? Just got 2x16GB g skill aegis 3200Mhz CL16 for my dads computer. Only 8 chips on one side. I bought these because the ones that was in his computer was 1Rx16. Guess I would've been better off ordering 4 8GB dimms instead.

[@camelcase811]

Yep, I've been using 4 x 8GB single rank modules for a couple of years (3800MTs cas16) to get the benefit of rank interleaving. Works pretty well. It's always worth checking the specific modules but in general 8GB sticks will be single ranked.

[@shaneholly11]

than thanks for the info

[@saiprasad8078]

Does mixing 1 rank and 2 rank cause any issues on normal use vs overclocking ?

[@CmdrSoyo]

well you will end up with triple rank and mismatched PCBs. as long as the ICs are the same it won't affect overclocking too much but memory controllers generally get very upset when you put more than two ranks in each channel

[@laharl2k]

yeah dual rank is heavy on the memory controller, i have 4x DR on a ryzen 3000 and the controller hits a hard wall at 3333mhz, anything over even just a little and its a no no. Voltage or timmings dont matter, it just will not boot higher than that no matter what

[@CmdrSoyo]

About what i would expect from quad rank

[@MrTrazz09]

question: does 2 sticks of single rank dimm (ex: 2 8Gb 1Rx8)have the same performance of 1 dual rank dimm (16Gb 2Rx8)

[@CmdrSoyo]

@@MrTrazz09 yes

[@sylwesterirla9246]

thanks

[@magnusnilsson9792]

I have a MoBo with 2 dead DIMM-slots hence not allowing dual channel, does it matter if I use 2 sticks or only 1 and single or dual rank stick(s)?

[@jordan-mn6yy]

definitely go with dual rank sticks in that setup. and depends on which 2 dimm slots are dead. if one of the second channel is dead than ya you're stuck with single channel and having 2 modules or 1 wont effect the speed. but if you have dual channels working, go with single rank modules cause the speed that can be reached is objectively higher it's well documented everywhere. In reality, in fact, single rank is faster than dual rank unlike the title of this video.

[@magnusnilsson9792]

@@jordan-mn6yy Both channel 2 slots are dead(refuses to post), but both channel 1 slots are still working. I have tried all possible combinations with 1 or 2 sticks. I haven't tried 3 or 4 sticks though. I haven't checked if my sticks are dual rank or not, but my concern is if that matters at all.

[@reubenlaitthma1048]

So when it comes to laptop ram/sodimms, how do I identify x8 vs x16? 8 chips on one side means x8 and 4 chips on one side means it's x16...?

[@Jouniii]

I think that 1Rx8 has 4 chips on both sides and 1Rx16 has 4 chips on only one side. But i guess the 8 chips on 1Rx8 could be on the same side too. Also a 2Rx8 has 8 chips on both sides.

[@cdonovancp]

Thanks for your video. I just bought four dual rank b-die 16gd 3600mhz cl14 sticks of ram. I was wondering would my system be stable if I run all 4 sticks of ram at DOCP so not really overlocking the ram? I have a 5800x3d on a Dark Hero x570 board. Thanks

[@CmdrSoyo]

buying B-Die just to run it at XMP is a huge waste honestly. if you buy B-Die you buy it for the overclockability the at XMP it's going to be just barely faster than a 3600 18 or 3200 16.

[@jashandeepsingh3666]

Sir, can you please explain.. At 5:23 you said.. "16x chips only have 2 bank groups,.. And at 7:01 you said "you have 8 bank groups on x16 chips."

[@CmdrSoyo]

x16 chips have 2 bank groups. one rank of x16 chips has 8 bank groups

[@jashandeepsingh3666]

@@CmdrSoyo I can’t understand 😶 One side you’re saying it has 2 bank groups and on the other side you’re saying that it has 8 bank groups

[@ketechin]

​​@@jashandeepsingh3666it's easy to undestand. X16 has 2 bank groups PER die CHIPS, and it has 4 chips, so total bank group is 2x4= 8 total bank groups..

[@dileep_hegde]

@@jashandeepsingh3666 that So-DIMM with 1Rx16 has total 4 chips 2 in each group so 4x2=8 bank groups and another one DIMM with 1Rx8 has total 8 chips 4 in each group so 8x4=32 bank groups. We will have total 64 bit in each memory channel, So, x16 has 4 chips as 4x16 bit = 64 bit and x8 has 8 chips as 8x8 bit = 64 bit.

[@panipu]

@@jashandeepsingh3666 One x16 chips has 2 bank groups. One rank consists of four of those chips so that's 8 bank groups per rank.

[@AG058]

There is a Crucial Ram that i want to buy 8GB ddr4 3200Mhz laptop Ram ..but the problem with crucial they don't mention anywhere if it is 1Rx8 or 1Rx16 information Is this Ram a 1Rx8 or 1Rx16 Ram ? I have another question , My laptop come with same Crucial Ram specs but is a Samsung with 1Rx16 .Can i Mix between both Rams currently cause i cant buy 2 memories now ?

[@ati4996]

you can mix dual rank and single rank, you can mix different ram speeds ,but only get lowest speed ram speed. there is a tool called thyphoon burner , it can clearly find out the ram is dual rank or single rank on spec page

[@AG058]

@@ati4996 thank you, i have dual and single rank on my device now.

[@TheLordismystrenght7]

​@@AG058 is there any performance issue?

[@AG058]

@@TheLordismystrenght7 no working great

[@jordan-mn6yy]

actually single rank is faster than dual rank bc it has been well documented that boards and cpu's are incapable of reaching the same ram speeds with dual rank as they are with single rank modules.

[@bobbyboygaming2157]

I suspect this dual ranks "speed advantage" is mostly hype that ultimately "cancels out". Because if you look at the "most overclockable DDR4 [Samsung B-die]", the only chips that can ever reach 4400 MHz CL19 are almost always single rank. Another thing I have noticed is that there is no 32GB per DIMM module B-die kit. It may be simply impossible to reach those high clocks with more capacity. There is something about having a lower number of chips with lower capacity which allows the chips to reach higher clock speeds, maybe having more chips and more circuitry also inserts new physical limitations? Or else, why is it that all the fastest DDR4 MUST be single rank? Conversely, the only way to reliably get dual rank is to get the highest capacities, e.g. 32GB per DIMM (is guaranteed to be dual rank in DDR4) because there is simply no other way to implement that capacity other than through dual ranks. You do talk about this at 11:25 minutes, but I would be very interested in seeing some type of controlled scientific test to truly see if the "dual rank" is better than the higher clocks of single rank. I would be very interested in this precise question because it is potentially a source of false advertising and false marketing claims etc.

[@vikastiwari7134]

Can i mix 16GB 3200 MHz 2RX8 with 16GB 3200 MHz 1RX8 and make my laptop 32 GB or should I stay with 16GB dual rank, which will be fast, pls suggest

[@aemssw2387]

U can mix ,it will not harm ur ram but increase ur memory , But all ram spec are same it gives slighlty higher speed,

[@crispysilicon]

Refresh

[@jordan-mn6yy]

if you get a single rank for your desktop pc that means you can populate all 4 slots and get faster ram speeds than if you populated all 4 slots with dual rank memory. So when ppl say get 2 ram now and later get another 2 for future upgrades it not a good idea if the 2 slots you fill now are dual rank memory cause you could get better speeds with single rank memory.

[@spg3331]

does this also apply to DDR5?

[@CmdrSoyo]

Yes

[@ketechin]

Just curious, so even clock is higher, but bandwitdh could be lower? Stated on asrock nova z790 as follow: 1DPC 1R Up to 8000+ MHz (OC), 4800 MHz Natively. 1DPC 2R Up to 6800+ MHz (OC), 4400 MHz Natively. I am afraid, since in ddr5 in the same bank group only 1 bank is refreshed and 3 other can still r/w (more efficient), so single rank could be faster, as stated in some of motherboard ddr5 as on Z790 asrock nova spec for example. Im not test it yet using thaipoon burner yet. Still curious, looking for sample ddr5 dimm.

[@AjrAlves]

Watching the video now, but my doubt is: 4xSR vs 2xDR EDIT: you addressed that at 2:50 thanks

[@CmdrSoyo]

2xDR will overclock better on most boards these days since the almost all use a daisy chain topology. filling all 4 slots on those lowers your max frequency by a lot.

[@LPgmxDan]

​@@CmdrSoyoeach in one of the channels? 1 dual rank in channel a and another in b?

[@2Fingz75]

hello i'm currently oc my dual DR 2sticks Bdie xmp 3200 c14 on a amd r9 5900x to 3733mhz c16 with stock VDDP VDDG,but without modificatino in need to tune my vddp to 975mv and VDDP 1075mv, but i cant go upper than 3833mhz, i change my RTT to 7/3/Disable or park 1, some change if i go to 3733mhz or 3800+, do you have any advice to help me to clock more ?

[@hermit1255]

.......what.

[@abritabroadinthephilippines]

DDR5 2C1R 7000+ MHz Stable & Fast > DDR5 2C2R 5600 MHz Stable & Slow

[@JustAGuy85]

Wrong right from the beginning. A1 and B1 are dual channel. A2 and B2 are the other dual channel. No need to listen further. If you've been building rigs like this... well, you've been gaming on single channel rigs. Just use CPU-z and double check your work. EVERYONE knows to skip a DIMM. Not only that, but we've moved in the motherboard industry from using DiMM A1 and B1 for a 2x stick build to using A2 and B2. 10 years ago, yeah, you used slot 1 and 3. Now it's 2 and 4 FIRST. You need to correct this.

[@walterryan4383]

'PromoSM' 💐