Threadripper PRO 5975WX CPU is coming out soon and it looks like I’m getting one. The ASUS Pro WS WRX80E-SAGE SE WIFI Mobo supports eight channel 3200 RAM.
Problem occurs when I go to the ASUS site and that Mobo. On the RAM compatibility list, my usual vendor (Corsair) only has 32GB listed, where I’m after 64 minimum. It also only has 4 sticks, not 8 and max speeds of 2166 / 2666.
If I open it up to all vendors I see Samsung and Mircon, but those look to be four stick SKU.
Can anyone recommend an eight stick RAM config for that CPU? ECC, non-ECC, don’t care. As long as it works and is reliable, I’m happy. Thanks in advance.
There are no 64GB UDIMMs. If you want 64GB modules, you have to get RDIMMs (which are the recommended type anyway). Samsung, Micron and Kingston all have 64GB RDIMMs.
Then pick some compatible 8GB or 16GB module from the QVL and buy 8 of them. But check support and manual first before buying 8 non-RDIMMs, because I suspect the memory controller doesn’t really like 8x normal DIMMs. 3200MT/s is guaranteed with 8xRDIMMs, same as EPYC.
I’m running 8x 32GB 3200Mhz ECC UDIMMs from Kingston in the ASUS Pro WS WRX80E-SAGE SE WIFI with the 3975WX Pro. They are also on the QVL list. So it’s possible, but anything larger needs to be RDIMMs last I checked.
Oh if you are talking about totals then you can buy almost anything you want…
I am personally using quad channel on my regular TR (non - Pro) 3960x w/ Mushkin DDR4 3600.
There shouldn’t be any issues with this memory. I can get the full speeds out of it, so if you went with 4x 32GB Kits it should also work.
I don’t really care about QVLs in general; I have always found them to be extremely lacking to say the least.
I’m following this thread closely as I’m looking at building a TR Pro system. I would like to have a 250GB 8x32 configuration at 3200, but I do not need ECC and would like lower latency numbers. I have some flashy Gskill dimms that I’m hoping to get to work at full spec, but I would have to up the voltage to 1.35 and hope its stable
@wendell Regarding the discussion in the video on whether to populate all 8 memory channels. I would argue that if you care about performance, that would be a definite YES! You did recommend that, but not strongly. However my testing has shown that the penalty for using less than 8 channels is much larger than I expected.
The below results show the max records/sec ingested into Elasticsearch on a 3995WX using 8, 6, 4 and 2 channels. While having all 8 channels populated was clearly best. What was surprising is how having 4 or 6 populated is no better than only 2. It seems that when less than all 8 channels are populated the memory controller enters into an entirely different mode of sharing memory access with the CCXs.
As noted this test was on a 3995WX. The 5995WX may behave differently, and of course other workloads may be less sensitive to memory bandwidth/performance.
