Annoying Whine from System at Idle

[Eluder]

So, I'm experiencing a really annoying whine, probably coil whine as many have described in other threads, but for the life of me I can't figure out what it is.

It appears to be evident only at idle as if I load the GPU or CPU, the fans tend to drown out the sounds, especially the 6950's fan.

I thought it was the GPU originally, but I popped in my 4850 from my HTPC and the sound was still there, although it seemed to cycle at a different rate.

I've also killed off all fans in the case via the connected fan controller, except for the CPU fan and the exhaust fan, and it's still there. I will probably try to disconnect the exhaust fan and see if it's that, but it's a Noctua so I doubt it's the one producing the whine as it sounds like it's coming from the front area.

Anyone have any ideas what it could be and what I could do to isolate it?
It's driving me insane and I have to get it resolved somehow.

System specs are up to date for detailed info.

Thanks!

[vohiep84]

Have you tried isolating your PSU?

[Eluder]

That's next on my list to try, I've got an Antec TP Trio lying around that I can use, would be disappointing if it is the PSU considering it's a Seasonic, but I guess all brands have their issues.

[_dangtx_]

disconnect the fan controller. some of them dont play nice with whatever fans.

physically unplug it

[Eluder]

I'll try that, it's a Scythe Kaze Master and I've had it for years without issue, but I guess that could be a new source.

Simply unplugging it from power will suffice or do I need to actually remove it from the case (can't see this being required, but you never know).

[zoob]

Try disabling the advanced CStates in your BIOS... C3/C4/C5/C6 or whatever options you have.

Following combos that I've tried that have PSU whine because of these C-States:

Gigabyte EX58-UD4P + Seasonic S12-600
Gigabyte H55M-USB3 + Seasonic S12-600
Gigabyte H55M-USB3 + Corsair AX750
Gigabyte H55N-USB3 + Corsair VX450

[Eluder]

You know, I read the same thing elsewhere with the Asus board, which is what I happen to have, but didn't think about it much.
What are these CStates anyway? Some power saving or something?

Yeah C states are to do with power savings.

[Eluder]

Prelim testing shows disabling C3 and C6 settings resolved it, but I'll be testing tonight to make sure it's gone.
So what aspect of power saving do these two options do though cause my idle clocks were still lower, so I'm happy with that since it means my system runs cooler/quieter when I don't need a lot of CPU power.

Thanks for the tips folks and I will report back when I test further.