On 06/02/11 07:00, Chuck Munro wrote:

Hello folks,

I'm having a difficult time trying to figure out why the CPU cooling fans run at full speed on my Supermicro X8DAL-3 motherboard. There doesn't seem to be any variable speed (the fans are PWM compatible) ... they either idle at almost nothing, or suddenly burst into a high-pitched scream that gets my ears bleeding after a few seconds. Once they jump to warp-10, they remain there.

The "Super-I/O" chip on this board is a Winbond W83627DHG which does the temperature and voltage monitoring.

Is anyone aware of which driver or kernel module I need for that chip in order to get control of the fans? The Supermicro web site and the board's manual aren't any help. Fresh installs of CentOS-5.5 and RHEL-6 don't exert any control by default. Installing the lm_sensors package and probing with the 'sensors' command didn't help either.

Slowly going deaf .......

Chuck

Hi Chuck,

The correct kernel module for your chipset is w83627ehf.ko. I'm not sure the driver actually controls fan speed, I thought it was more for monitoring (fan speeds, temps, voltages) but I could be wrong. My current system (not a Supermicro) controls variable fan speed from options within the BIOS. I can enable/disable fan speed control and select either voltage or PWM based control.

The stock w83627ehf driver in RHEL5.5 is oldish (they were updated in 5.5 I think but are still over a year old now). ELRepo.org have an updated driver available (kmod-w83627ehf) based on a backport from kernel-2.6.34. I've just checked upstream and a few more patches have been committed since kernel-2.6.34 and the current kernel-2.6.37 so I'll look at updating the elrepo driver with those latest patches.

Hope that helps.