EPYC 7002 and RAM speed questions

[scline]

Shopping around for some RAM on a new build I am throwing together. This is using an EPYC 7502(32c/64t) CPU. I understand RAM speeds affect the Infinity Fabric, and 3200 is the target for best performance, but just how much performance increase would we be talking about when comparing:

64GB LRDIMM @2400
64GB LRDIMM @3200
64GB RDIMM @3200

This is mainly for home labw/proxmox if that helps. Just having a hard time understanding just how different, say 2400 vs 3200 is with real-world performance. The 2400 speeds are roughly half the price is why I am asking.

Thanks (^_^)/

 

[Kizune]

In my personal rig with EPYYC 7742 i'm using RDIMM 2666 and just running it at 3200. Works just fine. I would not put that into a production server but for personal workstation or Plex server - i do not see a problem.

 

[ano]

7502 is "so slow" that most workloads doesnt really show a huge diff between 2133, 2400 and even 3200!

now if you have a 7763, or 75F3 or similar, it matters, our workloadss are about 20-25% better with 3200 ram on a 75F3 as an example

with 7402, there is a 3-5% diff between 2133 and 3200!


long story short, save your money unless you know what your doing

 

[RolloZ170]

In my personal rig with EPYYC 7742 i'm using RDIMM 2666 and just running it at 3200

The Infinity Fabric will have a maximum speed of 1467 MHz (lower in some platforms), resulting in a single clock penalty to transfer data from the memory channels onto the Infinity Fabric to progress through the SoC. To achieve the lowest latency, you can set the memory frequency to be equal to the Infinity Fabric speed

https://developer.amd.com/wp-content/resources/56745_0.80.pdf

 

[scline]

Thank you all (^_^)