EPYC Memory Configuration

Hardware Motherboards
1

Followed Level1 on YT for a while. Seeing the Epyc workstation build has motivated me into building an EPYC system.

(that and getting a stunning deal on a 7401P…)

So, finding SP3 boards in the UK has proven to be difficult, however, I seem to have found a supplier that can sell me a Gigabyte MZ01-CE1 (ATX, no 10GBe - dont need it…).

I planned 8 (new) sticks of 8GB 2400 mhz DDR4 ECC to make 64GB, fully populated.

For similar money, I could go for 4 sticks of 2nd hand Samsung 32GB DDR4 2Rx4 PC4-2133P

It will become my replacement ESX 6.5 server where I run a number of Xubuntu virtual desktops, so no multimedia heavy lifting/encoding etc

  • Am I going to see much difference dropping from 2666/2400 to 2133?
  • How big a deal will it be to only populate 4 slots ?

My gut tells me twice the memory will outway the speed but I am really not sure about half populated vs fully populated…

Any advice gratefully received…

2

This will surely help you make the right choice for your workload.
In my opinion it’s not worth because you’re resorting to a dual rank DIMM for just 8GB per stick. I don’t think 2R DIMM at 2133 is faster than a 2400MHz 1R DIMM. You’ll probably be fine with the 32GB kit if you’re not going to hit that machine with significant loads, but it might stutter a bit if four VMs on it are decently loaded. But why get that kit instead of the 64GB new kit, which is surely much better in terms of throughput?

3

Thanks for the link (which I hadn’t seen for some reason) and the reply. I will read and absorb; its been a while since I had to fuss with memory.

When I said " 4 sticks of 2nd hand Samsung 32GB" I meant 4 sticks of 32, so 128GB in total (twice what I would get new)