ryzen 5 5600 + 4000mhz ram

gasolin · February 10, 2022

Im waiting for a Msi B550 gaming plus + a ryzen 5 5600x

I have 4000 mhz cl 18 g skill ripjaws v ram and wanna know if it it's a performance loss running them at 4000mhz with a ryzen cpu/mb, because i ask is that i couldn't fin anything using google

I know some have said it's a performance loss if your running ram above 3733mhz (sweetspot) do to fabric not being 1:1,

HOW ever when using youtube i don't see any performance loss running ram above 4000mhz with ryzen

Chris Pratt · February 10, 2022

First off, don't trust anything you see on YouTube.

Ideally, yes, your RAM clockspeed should run 1:1 with the FCLK. The "sweet spot" for that is anywhere from 3600MHz to 4000MHz. Lower and you'll be leaving some amount of performance on the table. Higher and you have to run async. 4000MHz is borderline. Theoretically, Zen 3 can hit a 2000MHz FCLK, but in reality that's exceedingly rare. However, you can simply downclock it until you can hit the maximum FCLK. If you do end up running it async, that can carry a performance penalty of up to 25%, but it's highly dependent on the use case. Depending on the game, you may notice nothing, or it could be significant.

For what it's worth, since the 5600X is a single CCD design, running 1:1 is not as important. It still effects communication with the I/O die, but you don't have to worry about communication between multiple CCDs with higher end parts like the 5900X or 5950X.