Fan Control - GPU & CPU Competing/Overriding Same Fan


New Member
I have an Alienware M17X R3.  It has two fans, one by the GPU and one by the CPU, but since the Dell EC doesn't play nice with HWInfo I have to use the default which is to control both fans as one.

I have a fan control defined looking at both my GPU and CPU temperatures, and changing fan speed based on either's temperature.  I also have respin defined at 2 seconds, because otherwise I could be playing a game with high GPU load but if the CPU drops below a threshold the fan might turn down and never spin back up again as long as the GPU temp is staying constant and not moving across thresholds. 

The issue occasionally arises when I'm doing something CPU-intensive but with little/no GPU load.  The fan control will spin the fan up to max as the CPU initially gets hot, but then at some point the GPU temperature will start overriding on the respin commands and will tell it to turn the fan down or off, even though the CPU is very hot.  This doesn't seem to be an issue the other way around, mostly because CPU is probably rarely low enough when I'm under heavy GPU load.

Anyways, is there a way to get these two fan controls that share one fan to play nice with each other and to never turn the fan off or to a lower speed if the other control still thinks the fan should be higher?  Example:

50C - 0rpm
55C - 2400rpm
65C - 4000prm

45C - 0rpm
55C - 2400rpm
63C - 4000rpm

So I have these both going at the same time, controlling the same fan, with a 2000ms respin setting.  The GPU is stable at 40C and the CPU spikes up to 70C.  The fan will spin up for the CPU, and then the GPU temp will at some point tell it to spin back down to a lower speed.  What I'm asking is if there's a way (or an enhancement/option that you can add to HWInfo) so that no command will ever be given to slow down a fan if another ruleset for a different temperature sensor thinks the same fan should be going faster.  Basically, make it so in this scenario my CPU who thinks it should be at 4000rpm will always win over my GPU who thinks it should be at 0rpm.

Looking forward to your feedback.



HWiNFO Author
Staff member
I'm sorry, there's no such option available - both controls act independent and can force the fan up/down depending on the particular thresholds.