# Pros and cons of disabling C-STATE (and C1E)



## dkg_

I've had a nightmare building a 1155 PC because all 3 motherboards of differant brands I've tried give of coil whine buzz from around CPU area with 3 differant PSUs.
So it seems I might have to admit defeat and disable C-state in BIOS to fix the noise.
I am using MSI P67A-C65(which advertises whistle free) and c1e is disabled by default and c-state fully enabled. 
c1e doesn't make any differance to the noise so is that best left disabled shall I enable it?

I've done alot of testing myself and looked all over the internet for answers but not much luck in finding answers.
Here are my findings anyway:
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c1e-enabled/c-state disabled(no noise): Idle: 1 volt/1600MHz/0%Turbo booster/26°C
Orthos/load: 1.2V/3.4ghz/25% Turbobooster usage/50% CPU usage(maybe software bug)/43°C
Crysis CPU test avarage fps:27, 29, 29, 29


c1e-enabled/c-state enabled(coil whine): Idle: 0.93 volt/1600MHz/0%Turbo booster/24%
Orthos/load: 1.2V/3.*6*ghz/80% Turbobooster usage/50% CPU usage/43°C
Crysis CPU test avarage fps:26.8, 28.8, 29, 28

c1e disabled/c-state enabled is same as above.
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So if anything I seemed to gain FPS with c-state disable even though my CPU clock is 2000mhz slower and turbo booster won't seem to go over 25% with it disabled, it also ran with more volts on idle without it.

C1E didn't seem to change anything.

Could anyone please explain the pros and cons of these and if the differance will be as small as it looks or any advice regarding the squeal/whine itself.

I know it's asking alot, but motherboard manufators won't help and I built this PC specifically to run quietly(i don't know why squeal/whine/buzz/fans/HDs etc bother me so much but I end up with headache every day..).
Hope someone can help. Cheers


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## JimE

For the BIOS to have full control of all the features of the newer cpus, they all need to be enabled.

Maybe this will help (taken from another post):

That was the case for older CPU's but the i3/i5/i7 benefit from both, SpeedStep is better for changing the multiplier/voltage but C State has additional benefits on the new Intel CPU's, instead of the whole CPU either being on/off/idle parts of the CPU can now be turned on/off or set to idle and this works in conjunction with intels Turbo Mode.

So basically they did do the same job but there are benefits to having both on when it comes to the new i3/i5/i7 CPU's.

you will want to set CxE Function to C6 to get these new benefits alongside having SpeedStep enabled (they can work independent of each other but its best to have both enabled, be warned though with newer EVGA BIOS's having CxE Function enabled will allow the higher Turbo Mode multipliers to kick in and could make your OC unstable, if this is the case disable CxE Function but you could keep SpeedStep enabled if it still works, on the X58 Classified the voltage part of SpeedStep does not work with a manually inserted Voltage, it does however still work on the E758 3X SLI board with a manually inserted vCore voltage, this is just due to the components used and how the boards are set-up due to the segments they are for, Classified being a primarily overclocking board when power saving features are secondary. There are still work around for the X58 Classifieds using the ECP, this should allow you to OC the CPU but use an AUTO voltage which would allow the voltage part of SpeedStep to work, for further information on this please PM me)


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