Question 9700k, BCLK overclocking and DMI voltage

[80251]

I read somewhere that on Coffeelake -- or maybe previous gen. LGA1151 CPUs -- that if you resort to BCLK overclocking you're supposed to increase the DMI voltage substantially (i.e. to 1.291V or more when the default is somewhere around .984V). For some reason this even applies to memory overclocking. But is this true or just myth?

 

[Lutfij]

Might want to read this;
https://www.techpowerup.com/forums/...150-mhz-cause-instability.313552/post-5100286
and it's for this reason you don't BCLK overclock...at least not in the long run.

What motherboard are you working with?

 

[80251]

LOL, you found my old post about BCLK o'clocking. It's the same system though: Asrock z390 Taichi, 9700k, 4090.

From what I now understand BCLK is no longer tied to PCIe bus speeds, they're asynchronous. The only way to increase FCLK speed is by BCLK overclock.

Do I need to increase the DMI voltage though? Maybe oveclocking BCLK affects the DMI bus speed? The Intel spec sheet for coffeelake doesn't mention DMI voltage limits or even recommended values.

My present BCLK is at 148.37. So far I've done 4 hours of prime95 large FFTs and 6 hours of orthos 6-core testing.