Trying to run 16.2 on a stock Dell Inspiron 580s and things were fine until my CPU fan acquired the bad habit of surging/oscillating between 300 RPM and 3000 RPM. This problem sometimes happens right at boot and other times while watching videos. Closing out all programs does not solve the problem. Once it starts it will not stop.
Needless to say, this is extremely annoying.
Have searched the Forum and elsewhere and this does not seem to be a common problem. I've re-installed 16.2 numerous times to no effect.
Anybody have any insight into what may be going on?
It might have to do with your CPU governor... with load, the ondemand governor ramps CPU frequency up to maximum (hence maximum heat production) and leaves it there until the load is gone, then it ramps it back down. This is to make the machine feel more responsive.
Try changing the CPU governor to conservative to see if fan behavior changes... the conservative CPU governor ramps the CPU frequency up in small steps (which is user-configurable to as low as 1% of maximum CPU frequency per step) if load is above a certain user-configurable threshold, and down in small steps if load is below a certain user-configurable threshold.
Also check in your BIOS / UEFI setup... some of them have a utility where you can configure the fan speed ramp curve (ie: x RPM for x' temperature, y RPM for y' temperature, z RPM for z' temperature, etc.)... it may be that it's somehow gotten configured to ramp to maximum and stay there until the CPU reaches the lowest temperature setpoint, whereupon it slows fan speed to minimum.
Navigate to Zorin menu > System Tools > Startup Applications.
Add the following:
Name: CPU up_threshold
Command: sudo sh -c "echo 99 > /sys/devices/system/cpu/cpufreq/conservative/up_threshold"
Comment: Sets CPU up_threshold
You can change the '99' to whatever CPU load you want.
Name: CPU down_threshold
Command: sudo sh -c "echo 98 > /sys/devices/system/cpu/cpufreq/conservative/down_threshold"
Comment: Sets CPU down_threshold
You can change the '98' to whatever CPU load you want.
Name: CPU freq_step
Command: sudo sh -c "echo 1 > /sys/devices/system/cpu/cpufreq/conservative/freq_step"
Comment: Sets CPU freq_step
You can change the '1' to whatever step in frequency you want (in percentage of maximum frequency).
Name: CPU ignore_nice_load
Command: sudo sh -c "echo 1 > /sys/devices/system/cpu/cpufreq/conservative/ignore_nice_load"
Comment: Sets CPU ignore_nice_load
This one ignores CPU loads that are low priority... so if you've got a long-running task that tends to bump up CPU frequency (for instance: Conky, started using nice /usr/bin/conky -p 10 19), this'll fix that.
The "conservative" setting did not seem to make much difference.
But here is what does seem to be working, though who knows if it is in fact any sort of fix:
Found a fan control program called Coolero (its creators seem unaware that in Latin American slang, a similar word derived from culo has a rather derogatory meaning.) Installed something called l-m sensors, along with responding "yes" to a dozen or so requests to run various probes. When properly set up, Coolero allows control of my CPU fan via something called it8721, which, when set to Custom, pretty much handles the problem. Coolero doesn't make a whole lot of sense otherwise (What is the y-axis supposed to represent? RPMs? Why are both CPU and motherboard fans represented by the same symbols?)
Anyway, will keep you posted how this works out. Thanks for your help.