yoshy-
Sorry, thought I'd put that. Motherboard is ASRock H81M-DGS R2.0 The BIOS has a whole load of fan customisation available but the fan always runs at the same speed.
I've tried fancontrol. When I run the pwmconfig none of the fans change speed so it says they aren't able to be controlled.
@Velocio I'm mixing terminologies a little. The CPU has one of these http://www.nofancomputer.com/eng/products/CR-80EH.php
as it's passive the air in the case heats up under load which is what I want to turn a fan on to clear.
The temperature I'm measuring is from the CPU/motherboard.The case fan is actually plugged into the CPU fan jumper, although I've also tried it on the chassis fan jumper. I was assuming that they were sensor bound as there are BIOS settings for fan speed but they don't seem to do anything.
I can find very little info on safe CPU temps. If 85C is OK for two or three hours (and rarely that) then the option is just to leave the passive cooling. It idles around 35C or so so there's no issue there.
Cheers
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aggi
A PC problem that's really pissing me off.
One of my PCs spends most of its time under little load and has a passive CPU cooler so I don't need a fan. Occasionally it does a load of transcoding which currently sees the CPU temp get up to about 85 degrees.
I want the case fan to turn on at a certain temperature and off when it drops below that. The BIOS utility doesn't seem to make any difference to the fan speed,, just runs at full speed regardless.
LM-Sensors on ubuntu shows the fan speed and CPU temp but can't control them.
I've tried the 3 pin fan that came with the case and a 4 pin PWM fan and neither makes any difference.
Am I missing something obvious. Is there another option?
Fans with built-in temperature cut-off switches don't seem to exist. In theory I guess I could have something activated by USB but that's beyond my very limited programming skills.