Windows 10 kills fan speed control after sleep and overheats the CPU

[NeoPTLD]

I'm working on a legacy Dell Optiplex 380. The fan speed control is tied to CPU temperature. System was shipped with Windows 7 Professional 64 bit and Microsoft upgrade wizard assessed it can upgrade to Windows 10.

It has a serious problem that prevents the use of sleep. It works ok if the system does not enter sleep since last boot but when the system wakes up from sleep, the fan speed control is disabled and does not respond to CPU temperature. When the CPU is under load, it will heat up and bounce on the thermal throttle. Fan speed control is restored after a reboot and stays working unless the system goes to sleep.

I put a blank 160 GB drive and did clean install of Win 10 Pro 64 bit build 1607 but the problem persists. What is controlling the CPU fan speed and where do I start looking to figure out what's killing it? I would like to know more for personal learning than anything. I thought the fan control was managed on hardware level on a desktop board but I can take control over it using HWinfo and force the fan on maximum or minimum so I think Windows is somehow doing something to take over the fan control and locking it at minimum. Thermal throttle is there to prevent immediate failure of CPU in the event of a problem such as a fan failure or blocked airflow but I believe letting it bounce on the limiter on a regular basis is not a good idea.

Dell Optiplex 380 G41/ICH 7 Core 2 Quad 9650

Checklist
BIOS A.07 (latest)
Reset CMOS
Reinstalled Windows
Reset powercfg manually

Any wisdom on correcting this issue? Please do not say "disable sleep".

 

[mpo]

Have you tried reinstalling the chipset drivers or the Dell Command (or whatever their management system is called these days) application?

 

[NeoPTLD]

There is no W10 64 chipset driver for G41 and ICH7 offered for download on either Intel or Dell page and I just let it be whatever was installed by W10 64 1607.

Dell's webpage says this PC is not tested for Windows 10.

 

[mpo]

It can't hurt to try the Win 7 chipset driver off of the Dell page.

 

[Ketchup]

Every Dell I have had/used/worked on does fan speed settings through the BIOS, based on temperature. (not that they were ever user adjustable). One time I took a Dell from Windows Vista to 7 to 8.1, had no effect on the cooling fans. Because I don't think that the fan speed has anything the OS on these machines.

Are you sure the Windows upgrade did it? If you go back to 7, does the fan speed go back to normal? You might want to see if there is a BIOS upgrade available for your model.

 

[NeoPTLD]

Every Dell I have had/used/worked on does fan speed settings through the BIOS, based on temperature. (not that they were ever user adjustable). One time I took a Dell from Windows Vista to 7 to 8.1, had no effect on the cooling fans. Because I don't think that the fan speed has anything the OS on these machines. Are you sure the Windows upgrade did it? If you go back to 7, does the fan speed go back to normal? You might want to see if there is a BIOS upgrade available for your model.

I am not sure if you've actually read my post in its entirety.

 

[Ketchup]

Because I missed your BIOS update? Guilty, but that's the only thing I see update re-reading it. You might also want to look at your CPU speed upon resuming from speed. Is it still changing speed based on CPU load as it did before it went to sleep?

 

[piasabird]

Can you just set the fan to run all the time in the BIOS?

 

[NeoPTLD]

There's no setting in BIOS on this model. Some newer models do, but even then, your computer will sound like it's about to take off when you use this.

I think I've found the cause. It seems to be a flaw in Dell's embedded controller logic. Multiple people are reporting the same issue on other Dell systems from the same era.

http://en.community.dell.com/support-forums/desktop/f/3514/t/19490027

4 wire fans have a limited range of control and the addressable speed range is in relation to the maximum speed meaning that a 5,000 RPM fan has a higher minimum speed than a 3,000 RPM fan. So, I patched up this issue by installing a high RPM fan to raise the floor. It's a bit louder but CPU temps stay at an acceptable range with reasonable use even after sleep.