X399: Choose the best RAM configuration for 64GB

Hello everyone,

Since 1st gen Threadripper CPUs are on fire sale right now (~320€ for 1920X O_O) I decided to finally join the club of THREAD RIPPING :D. My motherboard of choice will probably be the ASRock X399 Taichi or the Pro Gaming, depending on budget and mood. Now to the title.

I want 64 gigs of RAM. I want B-Die, of course. So I have two options:

  1. 8x 8GB Single-Rank Kit
  2. 4x 16GB Dual-Rank Kit
  1. is bad because it populates all DIMM slots, and Ryzen/Threadripper doesn’t like that very much.
  2. is bad because it is Dual-Rank, and Ryzen/Threadripper doesn’t like that very much.

I would like to achieve 3200 CL14 speeds and not be stuck on 2933. That would be great.

So now my question, which of these two is the “lesser evil”, what should I go with and why?

I don’t need recommendations for a specific Kit. I’m more interested in the RAM topology and which of the two options overclocks better. After reading a bit, my inclination is to go with 8x 8GB SR, since DR seems to be a PITA to deal with above 2933.

Thanks for all your input in advance :slight_smile:

(PS: Not sure if this is the right category. I couldn’t find a dedicated RAM sub-forum… If this needs to go elsewhere, mea culpa :sweat_smile:)


Wait for it :smiley:

Now I’m getting excited. New video mayhaps? :heart_eyes:

According to this thing: https://benzhaomin.github.io/bdiefinder/

The dual rank flare-x 3200/CL14 is 8.8ns and 8.8ns is the fastest dual rank, but there’s other sources for dual rank 8.8ns.

There’s also 8.0ns and 8.1ns memory on the list that’s single rank.

I don’t think 8.8 vs 8.0 matters as much as you might imagine ie. Surely you’re not planning on getting 4500/CL18 ram and downclocking it to 3200/CL12 (or are you), just so you could squeeze that last bit of performance?

@wendell Come on IT Santa - stop holding out on us! Looking forward to the upcoming Gigabyte x399 Aorus Extreme review, and further details regarding the custom ECC production run. Can you please ensure the silkscreen layer of the later is black rather than toxic green, so that it does not clash with the colour scheme of the Extreme :slight_smile:

To my knowledge, without changing BCLK, you cannot achieve 3200 speeds on TR 1. YMMV…

I run dual rank 16G sticks x4 for 64GB @ 2933 CL16, 16 16 - 36. The ram is XMP rated for 3200 CL16, 18 18 - 38.

I regularly saturate the ram to its max. It is 100% stable. I was able to boot and run Cinebench @ 3200 XMP and scores were marginally different with 3200 getting 20 or so more points. The tighter timings making up for the slower speed. Very unstable though and of no use for any type of continual use and testing above 32GB use caused instant crash.

Without knowing what your main use case is it is a hard question to answer. For instance, I am already maxing my ram and could use more. If I had single rank I could not do this.

I regularly have my TR 1950x at 100% usage, ram at 100% usage and Vega 64 HBCC taking north of 15GB.

I would have liked to get tighter timings on ram, but they were not available at the time at a price justifiable to the ram I purchased.

You did not ask for brands, so i will not provide one. But there is, hands down, the best ram for TR 1 at CL14, dual rank 3200 16GB sticks. Even with those 3200 is doubtful.

The latency listed by the B-Die Finder is just simply a function of frequency (or rather transfer rate) vs. CAS latency (or CL) at the rated speed. For example, DDR4-3200 @ CL 14 will always produce a latency of 8.75 ns and DDR4-2933 @ CL13 would produce a latency of 8.86 ns, regardless of single or dual rank. Since the communication of Threadripper dies happen via Infinity Fabric, and Infinity Fabric scales with RAM frequency (always running @ half the RAM frequency), [email protected] will perform better than [email protected], even though the latency difference is miniscule.

Actually I was planning to go with a 4133 Kit (CMK64GX4M8X4133C19 for those interested) and run it @ 3200 since it costs me the same as a G.SKill [email protected] Kit.

You mean dual rank, right? 'Cause I have seen 4x 8GB single rank kits reach 3466 and up on 1st gen Threadripper without changing BCLK.
[email protected] is very rare for B-Die, so I’m assuming you’re running an MFR kit (please correct me if I’m wrong.) For MFR, [email protected] isn’t bad, it’s very rare for MFR to hit 3200 speeds, and if they do, it’s CL18 most of the time anyway.
Use case for me is multi-purpose workstation: Debian host OS on ZFS file system, multiple Linux and Windows VMs for development and software testing and occasional gaming in the evenings. I have been running on 16GB of RAM for the past year and 8GB of RAM for the 6 years prior to that. I don’t think I will need more than 64GB in the next while. But if I do I could always sell the current kit and get a bigger one.
Brands are kind of irrelevant for RAM, Corsair, G.Skill, GeIL, Kingston, TeamGroup, it’s all the same as long as it uses Samsung B-Die :slight_smile:

Basically, the only difference between 8x 8GB SR and 4x 16GB DR is the use of 4 less memory slots with the latter configuration. Two DIMMs SR per channel is essentially the same as one DR DIMM per channel. I have seen on Ryzen 7 that 4x 8GB SR clocks much better than 2x 16GB DR, reaching up to 3466 MHz @ CL14 for the single rank kit vs. [email protected] for the dual rank kit. After reading this I assumed that Threadripper would behave simmilarly, but populating all 8 DIMM slots seems to put considerably more stress on the IMC than just 4 DIMMs, which would make the DR option the better choice on Threadripper.

^This. All three of them, actually :smiley:

Yes and No. I have not seen dual rank above 2933 on TR 1. YMMV… It is the speeds in question, certain speeds do not fit the BCLK of AMD on TR 1. That is not to say you cannot get higher speeds, just certain speeds.

CL16, 18 18 is common B Die with GSkill and Team. See image below for my ram.

Sounds like Hynix speeds to me.

Yes. But I know of only one kit that guarantees B die. I have seen the same model numbers of kits have different dies.

Filling all slots will likely lead to more latency. Dual rank are faster than single at same speed.


Not sure I understand you correctly. So you’re saying dual rank above 2933 is possible, but not 3200 specifically? I read over on OCN about multiple people running dual rank with speeds of 3033, 3066, 3133, but not 3200 and not above.

From what I have researched, [email protected] is more often than not Hynix MFR. There is B-Die with these timings, just not sold exclusively as it’s more often binned down to CL15 or CL14. You may have gotten lucky to receive B-Die on your kit, but hey, at least you got B-Dies :smiley:

It’s true that the same kit is often sold with diffrent memory ICs, but not all of them. Some kits come exclusively with B-Die. I use two sources to research B-Die RAM: Benjamin Maisonnas B-Die Finder (@risk also mentioned this above) which feeds from HardwareLUXX’ Ultimate Samsung 8GBit B-Die List. The list is compiled from community and vendor contributions, always kept up to date and very accurate. The third column tells you whether the kit comes exclusively with B-Dies (ja=yes, nein=no).

Yep, was talking about Hynix MFR.

Dual rank is faster than single rank at the same speed and timings in a one DIMM per channel configuration because of rank interleaving. If you put single rank in a two DIMMs per channel config, you get basically the same result (Channel A: 1x 16GB DR DIMM [email protected] == Channel A: 2x 8GB SR DIMM [email protected] It is true, though, that populating all slots in all channels puts more stress on the IMC than only one slot per channel.

Sorry, should have been more clear. It is a time issue. On my first TR 1 build I had dual rank 3066 stable, so achievable. What I meant was I have yet to see anyone with B Die dual rank NOT achieve 2933. So when I said “I have not seen” I meant expectation, not possibility.

As for 3200 speed I meant single or dual. The TR 1 AMD BCLK does not allow certain speeds, 3200 is one of them. Without adjusting the clock they could not reach that speed. I do not think any new Agesa has addressed this for TR 1, but I must admit that I have not followed very closely in 2018.

Early with TR 1 I followed a Ryzen Memory thread on overclockers.net where users were scanning their ram and posting results. I saw lots of B Die with those timings in GSkill, Geil and Team. Other than before mentioned, they almost exclusively use Hynix or Micron.

In relation to this subject for choosing RAM. I have a question that expands on it, by using (ASRock) X399 combined with 128GB ECC.

I would like to know if that kind of board really supports 128GB ECC. Verified by someone that can testify.

I recently listened to @Wendell talking in a video (Threadripper 2 Update! ECC Support, Linux, and More!). His comments seems to confirm that ASRock 128GB ECC is possible on that motherboard (with Threadripper 2). But I’m not sure if he has tested the whole set of options. I assume I can wait for @Wendell to expand on the testing of the whole system so to give feedback to the public.

Before asking I did my research. Not conclusive:
· Looking at manufacturer (ASRock) manual and tech details, there is support for ECC for up to 4*DIMMs but not for the 8 of them. An informational detail that does not deny 128GB ECC, because not all memory combinations are really tested. So does not ensure, and does not deny.
· Looking around at an online shop in Europe (alternate), I encountered an advanced filter for products showing ASRock X399 has support for up to: 8 memory channels. The 16 channels support is showed for other motherboard brands (X399 chipset). So as showing not all motherboards with 8 module slots support more than 8 channels. Thus reducing the capacity of the motherboard of handling 128GB ECC. I do not entirely trust details on that shop (as sometimes there are small mistakes). But it was informative to me, as to think about 8 channels in 4 slots or 8 slots (what could be the differences or limitations).
(Edit: I edit my own text to clarify one point). The shop’s text mentioned in previous paragraph, stated memory-channels supported (in language spanish). But in my mind I thought it was badly described. So I assumed that motherboard feature was really linked to memory-ranks (1Rank, DualRank). As to indicate: supports 8/16 memory ranks in a 8 slots configuration. Which made some sense, when I thought there are modules like: 1Rank-8GB and DualRank-16GB. Thus my logic in mentioning this detail (as to limit RAM 128GB, 8x16GB [2Rx8GB => 16 ranks]).

My whole interest is because ECC is a must have. Specially when dealing with sensitive projects for engineering simulation that consume 128GB RAM. Thus my interest to verify X399 (ASRock) + Threadripper2 is an option. Or end consumer is pushed towards an (AMD Epyc) expensive workstation, to have 128GB ECC.

Should have a 2950 tomorrow. Will test.the 2990 posted fine and I’m 99% sure 8 sticks of 16gb ecc is fine but I’ll double check. I happen to have that crucial 2666 kit. 8 sticks.

costs more then the cpu lol

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Yes. Yes it did. Sadface.

Really depends on the use case scenario i guess.
But with 4x 16GB kits there is allways room left to expand.
And yeah populating all slots could lead to more stress on the imc.

So after watching the latest video, I came to the conclusion to just buy a 8x 8GB single rank kit and test. If I can’t get 3200 to work (or even 2933) I will just return it and get a 4x 16GB kit. I will report my findings here :slight_smile:

On another note: Damn, these DDR4 prices suck… 900€ for 64GB of 3200 CL14 memory. Literally thrice what I paid for my 1920X :cry:

Hence why I still have 64G instead of 128G. I would love to have 128G but refuse to pay the bastards the coin required.

I did get 3200 with GSkill RipJaws with a Ryzen 5 1600 with a MSI B350 board stable. But the trick was 2x 4G sticks.

Even when I gave a my ram a review on newegg Team Group responded with the AMD clock gen limitation. Surprising because I was giving them a good review.

Collusion I say, collusion! :money_mouth_face: But seriously, I wouldn’t be surprised in the slightest.

Helped a friend build a system recently, R5 2600 on ASUS Prime X470, 2x 8GB G.Skill F4-3200C14D-16GFX. Set D.O.C.P. in BIOS and everything just worked. Was not expecting that, was very nice :smiley:

I’ve read up a bit on that, seems your are right, but not completely. On early Ryzen, 3200 was impossible without BCLK adjustments. After a few AGESA updates, it now is possible, but only with good IMC, good B-Die and a lot of fiddling, even without BCLK. With BCLK tuning, even higher speeds are now possible, like 3466 und even 3600+ with decent timings.

I want to buy my RAM already, but it’s gonna be next month at the earliest. I still need to buy my board and a PSU and the funds dwindle steadily :sweat_smile: I want to test the 8x 8GB SR config. Really wanna know if I can get that to work amicably.

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