3200-CL22 vs 2999-CL21 vs 2666-CL19 for Epyc 7402P

[madeoutofcorn]

I am planning to build out a server based on 7402P 24 core CPU and I am not sure which RAM to go with. The server will be used in a lab test environment on ESXi and will be running 20-30 VMs total, some Windows/Linux VMs for “general use” and some virtualised Cisco stuff. I am planning to populate all 8 slots on the board to get all 8 channels.
I am expecting to run this thing at around 50-80% CPU utilisation and 80-90% memory utilisation.

At the moment, in my areaI have 3 options for RAM, all within ~$10 price difference. Planning to go with 8x32GB rdimms:

• 2666 MHz CL 19 Samsung Dual rank

• 2999 MHz CL 21 Kingston dual rank

• 3200 MHz CL 22 Kingston dual rank

I searched around the internet and I am having a hard time finding any benchmarks that would tell me which of the 3 would be the most beneficial for my usecase. I guess in my usecase, the “snapiness” would be more beneficial to the user experience rather than the total memory bandwidth.

Any suggestions?

[Adubs]

I dont think you’d be able to actually tell the difference from a perceived ‘snapiness’. That said the 3200 would bring faster IF clocks and therefore should be ‘more bigger more better’. latencies matter here too but IF is responsible for moving data throughout the entire CPU and not just in and out of RAM.

Thats my thoughts anyway. I could be wrong. I dont have that kind of setup.

[GoldenAngel1997]

I’d treat CAS as better consistency factor, for the listed speed rating. Also review memory density rating, for that processor, when incorporating your memory total. Wouldn’t be worth $$$ having higher speed memory, being kneecapped by multiple tiers.