Using DDR4 3200 Mhz RAM with Epyc 7451

[derkermit]

Hey,

I'm currently looking for a more powerful CFD workstation and thought about an Epyc build since they can be get quite cheap lately. But I can't use much of my current R7 2700X setup. Thus, I will need to buy new memory modules. The Naples design allows for 2666 MHz ECC RAM and I was wondering whether it is a good idea to buy 3200 MHz modules in order to be prepared for a possible upgrade to Rome in the future. However, I couldn't find any information on whether this is even possible. So my question is: Can I use DDR4-3200 CL22 modules with an Epyc 7451 CPU? Will it just run with the lower frequency and possibly lower timings?

Thank you for your help!

Regards, Alex

 

[alex_stief]

With the usual margin of uncertainty that comes with memory which is not on a qualified vendor list: yes, you can run DDR4-3200 on Epyc Naples with lower memory frequency.
As far as I am aware of, all DDR4 DIMMs have SPD profiles down do DDR4-2133. The motherboard and memory will negotiate suitable timings during the first boot.

Whether this is a good plan or not, who knows. But with memory prices currently on the rise, and DDR5 on the horizon, this right here might be the cheapest time to buy new DDR4 before it is replaced by DDR5.

 

[derkermit]

Thank you for your reply. I went for Dual Rank 3200 modules and they run stable at 2666 MHz with that Epyc 7451 on a ASUS KNPA-U16. The BIOS also allows to set 3200 MHz but I didn't try that yet. I couldn't find much information on infinity fabric clock speed of Naples but since it runs synchronous to the RAM speed in Zen 1 this might give a nice performance boost if it ends up stable of course

 

[alex_stief]

Please keep us updated if you ever try memory frequencies higher than DDR4-2666. It would be really interesting, at least for me.