CPU noise caused by 'Idle Processor' setting...Core Temperatures... Advice please

[martinlest]

I was being driven crazy by a high-pitched ‘chirping’ noise coming (as I could see, well, hear, on opening the PC case and investigating more closely), from an area around the CPU (i7-4790K, not overclocked (i.e. @ 4.00GHz. & 4.40GHzturbo)

Googling finally lead to this thread:

http://www.tomshardware.co.uk/forum/292915-30-high-pitched-noise-coming-area

and I followed through on these instructions there:

1. Execute: "regedit"
2 .Locate: HKEY_LOCAL_MACHINE \ SYSTEM \ CurrentControlSet \ Control \ Power \ PowerSettings \ 54533251-82be-4824-96c1-47b60b¬740d00 \ 5d76a2ca-e8c0-402f-a133-215849¬2d58ad
3. Change Attributes from 1 to 0.
4. Then, through the control panel - power - in the settings mode select power management processor. There will be an option disabling idle processor and high pitched noise immediately disappears.

It worked a treat, no more annoying squeaking.

But if the “All CPU Meter” gadget on my desktop is at all accurate (how close do these gadgets get to the real core temperatures? They can jump up and down ten degrees or more between one second reading intervals), as also explained in the same thread – and logically enough – the core temperatures, when running MS Flight Simulator (which is what this PC mostly does) are about 15 degrees C higher than when Idle Processor is enabled. (When MSFS is running, I get core temps between 45 degrees C & 70 degs (usually around 55). Adding 15 degs to those temperatures is not really acceptable.

More Googling lead to some other suggestions and I have tried disabling the C states option in the BIOS (Asus H97I M/B).In Power Management I have re-enabled the Idle Processor option.

Now, with C states disabled, enabling Idle Processor does not cause the CPU noise, as it did before.

However, before I found these posts, I knew nothing about C states, so I am posting here to ask further advice:

1. Is it OK to leave the C states set as disabled in the BIOS like this, with the Idle Processor setting in Windows Advanced Power Management set back to Enabled? My core temperatures are now back in the 50s, with MSFS running, and all is nice and quiet, as I say.
2. I read that having C states disabled with Speedstep enabled is not good. Do I need to disabled Speedstep as well? If so, why?
3. I also do sometimes put the PC into sleep mode. Once again, someone said that was not recommended. Again, could some kind ‘guru’ explain why that is the case (if it is)?

Any downsides to disabling C states in the BIOS in this way that I haven’t considered?

Many thanks for your help here.

Martin

 

[RunLuke]

Disabling c-states means nothing, it's basically just how much the cpu will "power down" and shut off when the computer idles, goes into sleep / hibernate etc. And by "idle" you mean minimum processor state set to 0%?

I also see no issue in sleeping your PC at all, it means nothing, they may have been talking about the olden days where windows didn't really like high uptimes. I sleep mine all the time.

 

[martinlest]

Thanks for the quick reply.

Not sure what 'idle' means in % terms. My BIOS has three options only for C states - Enabled, Disabled and Auto. It was on Auto, now it's Disabled and there's no more high-pitched noise from the CPU. Much better than setting processor Idle to 'Disabled', as there are no increased core temps.

And Speedstep is OK left enabled?

 

[lessthan0]

Speedstep doesn't have anything to do with power delivery to the CPU. All it does is control the CPU's speed under load and when it is idle.
Yes its ok to leave speedstep enabled.

 

[martinlest]

OK, thanks.