How to control fan speed on Compaq Presario under Ubuntu?

3

I have a Compaq Presario R4000 running Ubuntu Linux 9.10 karmic. The system runs very hot and one of the fans is wither never running or always running at the slowest speed. For a while I thought the fan was dead but I just updated the BIOS (Phoenix BIOS) and during the update, that fan suddenly kicked in at full speed!

How can I get that fan to spin up during normal usage? I have tried sensors-detect but all it found was k8temp, no fans...

(SpeedFan under windows found no fans either)

Josh

Posted 2010-04-25T21:49:22.637

Reputation: 7 540

Answers

2

It's entirely possible your laptop does not support software-based fan control. I have a Compaq Presario R3000 kicking around which does not, and, much like yours, only exposes some temperature sensors.

The fan in mine operated only as a hardware-controlled function of CPU temperature, and at a particularly lap-scorching range, too. Around 65+C it would kick up from it's lowest speed to about 60%-ish speed, and past about 70C it would hit 100%.

If sensors-detect found any sensor chips besides k8temp, however, there may still be hope: The utility you'd want to run to find controllable fans is pwmconfig. That gives you software-tunable control of fans based on sensor output, much like SpeedFan's automatic fan control mode.

Edit: Additionally, you might want to see if that second fan spins up under a particularly heavy CPU load. The linux version of Prime95 ought to be more than sufficient to generate enough heat to see if that's the case. Watch your temperatures, of course!

Jessie

Posted 2010-04-25T21:49:22.637

Reputation: 1 718

Well when running BOINC, the temperature rose to 144°C with no fan activity. So if it's controlled by hardware then the hardware isn't working. If doing a BIOS update made the fan run at full speed shouldn't there be some other software based way of getting the same effect? – Josh – 2010-04-26T13:59:44.933

2CELSIUS? 144C is alarmingly close to the melting point of solder. If you're absolutely sure it was C and not F, your laptop is in serious need of repair -- something is very, very wrong. Your CPU should have shut down well before it hit 100C. The BIOS updater probably poked some very low-level thing to get the fans spinning, as it was already in a position to do so. This was likely a significantly lower-level operation than can be easily exposed in modern operating systems, so for all intents and purposes, it's not software controllable. – Jessie – 2010-04-27T08:27:33.663

Well I have the temperature monitors in Fahrenheit, and two of them were reading 288°F I believe. The third one was far lower, but I forgot now what exactly it was. 110°F maybe? Something is clearly wrong and I suspect I need to be looking for a new machine. – Josh – 2010-04-27T17:57:47.343

Asked: 2010-04-25T21:49:22.637

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Active: 2010-04-26T02:16:15.327