Question Disabled CPU C-States and Sleep Mode

shmu26

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In my ASUS BIOS, I disabled CPU C-states, because I was experiencing random system freezing, and this is one of the things to try.
So far so good, but how does it affect sleep mode?
If I put this Win 10 desktop to sleep, the fans turn off. But since C-states are disabled, does that mean my CPU is still getting full voltage, and is likely to fry?
 
What are your system spec's?

Disabling C-states just means the processor won't turn off unused parts of the processor while it's operating to conserve power. Modern sleep (on a modern computer) in Windows10 is a hybrid sleep that entails writing a save-state to disk storage and shutting the processor off completely. C-states settings won't affect that.

Disabling C states is usually a last ditch attempt to keep a poorly configured, overclocked, or aging, system stable. Have you tried resetting CMOS to see if that's stable?
 
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shmu26

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What are your system spec's?

Disabling C-states just means the processor won't turn off unused parts of the processor while it's operating to conserve power. Modern sleep (on a modern computer) in Windows10 is a hybrid sleep that entails writing a save-state to disk storage and shutting the processor off completely. C-states settings won't affect that.

Disabling C states is usually a last ditch attempt to keep a poorly configured, overclocked, or aging, system stable. Have you tried resetting CMOS to see if that's stable?
It's a relatively new store-built desktop: i7, ninth gen. 16 Gb RAM, and SSD. ASUS Mobo.
I had the same problem with my old desktop, which was i5 sixth gen, if I remember right.
No overclocking, and no discrete graphics, on either system.
This problem never plagues me on Linux, only on Windows 7 through 10. (I don't remember back to XP). But it follows me from desktop to desktop.
 
...
This problem never plagues me on Linux, only on Windows 7 through 10. (I don't remember back to XP). But it follows me from desktop to desktop.
Windows has always had major problems with any kind of 'sleep' or power saving configurations. It can work for a while then just bug out for no apparent reason on me. So I'm not surprised.

I'd consider a clean install especially if you've been upgrading hardware on the same instance. That frequently fixes sleep and power management issues, and maybe some others you might not have noticed.
 
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Not to worry, sleep puts the pc and monitor into a very low power state, very near to full power off.
Modern motherboards support even lower power states, but I do not see that as a big savings.
Unless you need to preserve the contents of ram for a wake up, I suggest you set power options//sleep to no hibernate.
That avoids the writing of the contents of ram to a drive before entering sleep state.
That makes sleep/wake only a few seconds.
 
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shmu26

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Great, so I don't need to worry about my computer dying in the middle of its sleep. :)
So I will continue with this experiment whether it actually fixes the intermittent system freezing. This issue somehow manages to survive reinstallation of Windows, yet it is OS-specific, so I am just trying out various tricks that I find on the internet until something works...
 
Not to worry, sleep puts the pc and monitor into a very low power state, very near to full power off.
Modern motherboards support even lower power states, but I do not see that as a big savings.
...
I do like the hybrid sleep Windows is using on my motherboard. It still writes a save-state to disk but the turn-on time is a tiny fraction of time for a full hibernate, just a couple seconds because it doesn't go through BIOS POST process...and maybe because it's not a full 16GB memory image. Yet, like hibernate, if power to the system is lost it still recovers open apps and files and I can continue; boot just takes longer because it now has to go through a BIOS POST process.

The only thing is it's just a matter of time before it stops working again. Then I'll have to wait for a one or two more of Windows's semi-annual feature updates to get fixed. hah.
 
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I recently had a problem with a asus Z170 motherboard.
Windows would fail when waking from sleep.
This was a new issue after a windows update.
The resolution was to update the motherboard bios which was badly out of date.
 

shmu26

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Disabling C-states didn't fix it.
Maybe it's normal to experience a couple seconds of system unresponsiveness, every once in a while? It could be soon after system startup, or well into a session, and lasts for like 1 to 5 seconds, during which playback continues uninterrupted, but the active window appears slightly distorted and the system does not accept user input.
 
What is the make/model of your power supply?
Older power supplies did not support some of the low power c states.

In windows , go through power options, advanced options. Turn the options to power down usb ports when not in use and other similar settings
 

shmu26

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What is the make/model of your power supply?
Older power supplies did not support some of the low power c states.

In windows , go through power options, advanced options. Turn the options to power down usb ports when not in use and other similar settings
Antec NE550M 80Plus Bronze Modular PSU.

How would powering down usb ports help, if the freezing happens in the middle of the session, not right after startup?
 
Your psu is a modern unit. Good.

I think, by default, a usb port will be powered down after a period of inactivity.
That is not a good thing if you have usb attached devices ,like perhaps a usb backup device.
It may take a while for windows to decide that you are not going to use the usb device and lower it's power. Seems like a silly thing to do, but we are paranoid about using even minimal power.
Just a theory.

Since the issue has followed you from one pc to another, I would look at windows settings more carefully. In particular power management.
 
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