5900X FClk

[therealdippy]

I'm in the process of tuning my newly built PC, moving away from the default settings where I can. I bought some Corsair 4000MHz memory but was aware that in the PC default config it was running at 3200Mhz ish. I just enabled XMP in BIOS and rebooted and HWInfo shows that the current clock is now 2000.2MHz. If I have no issues is that all I have to do? I noticed that I can set the CPU FClk in BIOS - should I also set it to 2000MHz or should I leave it on auto?

 

[Joxeon]

The fclk should be set to half the ram speed else you gain a 10ns latency penalty, the issue is the system may not boot or if it does then it could have errors running 2000 fclk which if that's the case then you may need to drop the fclk down a bit and also the ram to match so you don't incur the penalty.

 

[therealdippy]

I installed Ryzen Master which showed that FClk was 1800MHz. So I had a go at setting FClk to 2000MHz. Initially I thought it was OK but when I launched a benchmark the PC crashed. I checked the event log and saw that it was full of WHEA errors. I then tried 1900MHz and my PC's fans and RGB went nuts and when I went back into BIOS it told me that it had been reset so I have to restore from a saved profile. I set FClk back to AUTO and FClk is showing 1800MHz. Should I just accept that 1800MHz is the limit of my CPU and in hindsight I'd have been better of buying 3600MHz memory?