C-States on AsRock X99 board.

jamieboo · 17 Oct 2015 at 10:48

Hello folks

My new X99 system is splendid in pretty much every way.

One minor problem I get is the occasional audio dropout from my Steinberg UR22 audio interface - which is a little annoying as I built this machine primarily for audio production.

I've been told that the various CPU powersaving systems can have this kind of effect on USB audio interfaces so want to start trying a few things in BIOS with C-States.

I have an i7 5820K (at stock) and an AsRock X99 Extreme6 mobo - and the relevant BIOS options are:
CPU C States Support
Package C State Support
CPU C3 State Support
CPU C6 State Support
Enhanced Halt State (C1E)

I could just try turning them all off, but I'd rather keep things at default if it's not doing any harm.

So, considering I know nothing about the order of 'deepness' of these various states, what's a logical and systematic order for me to try turning them off one by one?

Thanks very much!

mickyflinn · 17 Oct 2015 at 11:40

https://impact.asu.edu/cse591sp11/CStatesTutorial.pdf

jamieboo · 17 Oct 2015 at 12:08

Excellent! Thanks mickyflinn.
So, and forgive me if I'm being dim, would it be more logical to start my one at a time disabling from the 'deepest sleep' end of the C-State spectrum? ie start by disabling C6?
Also I'm wondering what 'CPU C States Support' and 'Package C State Support' are. They may be AsRock specific. Any ideas?
Thanks

wazza300 · 17 Oct 2015 at 13:50

Try c1e first,that's usually the main culprit of audio static,cpuwill still down clock if you use balanced power saving profile in windows

jamieboo · 17 Oct 2015 at 17:22

Thanks wazza300. I'll give it a go when I'm home.
In the meantime I'm trying to get my head round the logic of it.
Surely if I disable C1E (one of the lightest sleep states) won't the pc, while idling, just automatically jump to a deeper sleep state (up to C6) which is in turn slower to wake from?

wazza300 · 17 Oct 2015 at 18:48

idk,it depends which state is causing the noise

sometimes its just c1e,others it can be c6 ect but if you disable the others the cpu wont throttle at all,c1e disabled still allows cpu to throttle