256 GB memory predicament

[JAksel]

Hi,

Hope I am posting correctly. I am in need of assistance to figure how to get my systems up and running with 256 GB Ram. I do high poly 3D work with 3DS Max & Vray CPU renderer and the last couple of years my 128 GB Memory limit has become an increasing problem, which now has to be confronted.

 

My current setup is:

 

PC1: Workstation

Intel i9-7940X at 4.0 GHz OC, Asus Prime X299-A, 128 GB DDR4-2133 Hyper X Fury (8 x 16gb)

 

PC2: (1 of 4 render server)

AMD Ryzen™ Threadripper™ 2990WX, ASRock Fatal1ty X399 Professional Gaming, 128 GB DDR4-2133 Hyper X Fury (8 x 16gb)

 

As for as I can figure out I have two options:

 

Option A - ECC Memory

In my search for a solution this surfaced:  Puget Systems builds a i9-7940X with 256-512 GB of Samsung ECC Reg. memory on a Gigabyte X299 AORUS 7 as explained in this video by Matt Granger:  https://www.youtube.com/watch?v=ktum34xEUd0&feature=youtu.be&t=498 (The link is at the point were he explains about the RAM). 

 

Option B - non ECC (standard) Memory

G.skill makes this:  "F4-2666C18Q2-256GVK" -  https://www.gskill.com/qvl/165/184/1571733370/F4-2666C18Q2-256GVK-Qvl  - a non ECC "standard" RAM. The QVL lists both of my Motherboards as compatible.

 

 

So which one two choose? 

 

For PC1 workstation, according to Intel the 7940X only supports 128 GB of non-ECC memory:  https://ark.intel.com/content/www/us/en/ark/products/126695/intel-core-i9-7940x-x-series-processor-19-25m-cache-up-to-4-30-ghz.html. But if Matt Granger is correct, the Skylake memory controller will support up to 512 GB of ECC memory due to ECC "voltage regulation”, which brings me to option A.

 

According to ASUS the Prime X299-A supports up to 256 GB of 8 x DIMM, DDR4 Non-ECC, Un-buffered Memory. No mention of ECC RAM.

https://www.asus.com/dk/Motherboards/PRIME-X299-A/specifications/ So does this mean I can’t use ECC memory on this Motherboard? I could get another one, the Gigabyte Aorus would be an obvious choice. But for all other purposes the Asus Prime X299-A motherboard has performed outstandingly and swapping out motherboards is tedious at best. Also G-skill has the board on the QVL, so then what to do?

 

 

For PC2 renderservers AMD does not state a max memory for the 2990WX, but according to Wikichip the memory controller supports up to 2 TiB / 2199 GB: 

https://en.wikichip.org/wiki/amd/ryzen_threadripper/2990wx

, which should have me covered, but there is now mention of ECC vs. non-ECC.

 

According to Asrock the Fatal1ty X399 Professional Gaming only supports up to 128 GB of ECC & non-ECC memory.

https://www.asrock.com/mb/AMD/Fatal1ty%20X399%20Professional%20Gaming/index.asp#Specification. If that is the case, the motherboard could be replaced. But G-skill lists the boards as compatible, so very confusing!

 

I’ve looked into Xeons of course, which was my setup years ago, but the Single Core performance is just too poor at the moment.

 

If anyone could help with this ECC/non-ECC/CPU/Motherboard predicament, it would very much appreciated!

 

 

[GoldenLag]

I dont believe that threadripper or skylake X will run on Rdimms. 

 

 

The motherboard and CPU will run as high memmory capacity as you can fit. 

 

It will probably run at less than rated speed tho. 

 

128GB per 4 dimms shouldnt be an issue. 

[JAksel]

Thanks for your reply GoldenLag!

So if I understand you correctly with 8 dimms on both boards I should be able to run 2 x 128GB non-ECC memory, but probably at a lower speed?

 

cheers

 

 

 

7 minutes ago, GoldenLag said:

I dont believe that threadripper or skylake X will run on Rdimms. 

 

 

The motherboard and CPU will run as high memmory capacity as you can fit. 

 

It will probably run at less than rated speed tho. 

 

128GB per 4 dimms shouldnt be an issue. 

 

[GoldenLag]

5 minutes ago, JAksel said:

So if I understand you correctly with 8 dimms on both boards I should be able to run 2 x 128GB non-ECC memory, but probably at a lower speed?

Lower than their rated speed yes. Say you buy 4 kits of 3200mhz 2*64gb kit (probably the cheapest way of doing it)

 

And they may only run at say 2933mhz. 

 

6 minutes ago, JAksel said:

ECC memory

You can run regular ECC memmory sticks, but they have to be non-Rdimm. Just regular dimm. 

 

Then again. You will likely never really have to worry about bitflipping. Its stupidly rare om ddr4. 

[JAksel]

So I'm aiming for a total of 256GB. These Gskills https://www.gskill.com/product/165/184/1571734065/F4-3200C16Q-128GVK are the only ones I can buy here in Denmark at 3200 mhz. 2 kits of 4*32GB 3200mhz are reasonably priced. 2*64 are all unavailable. I'll give them a go!

 

Thanks for your timer, GoldenLag