http://www.technologicalwanderings.co.uk/taxonomy/term/34 en http://www.technologicalwanderings.co.uk/node/19 <div class="field field-name-taxonomy-vocabulary-1 field-type-taxonomy-term-reference field-label-above"><div class="field-label">Keywords:&nbsp;</div><div class="field-items"><div class="field-item even"><a href="/taxonomy/term/33">amd</a></div><div class="field-item odd"><a href="/taxonomy/term/34">cool</a></div><div class="field-item even"><a href="/taxonomy/term/35">fan speed</a></div></div></div><div class="field field-name-body field-type-text-with-summary field-label-hidden"><div class="field-items"><div class="field-item even"><p>I have an AMD Athlon X2 5600.</p> <p>I found that as soon as my Linux box used some CPU time and got a bit warm as a result it would increase the CPU fan speed to 3,000 RPM or more. As expected. However, it would then never drop back down to the 2,000 RPM idle speed.</p> <p>The reason is that the kernel defaults to 'performance' mode for cool'n'quiet.</p> <p>Take a look at:<br /> # cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor</p> <p>To see what your kernel/CPU supports:<br /> # cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_available_governors</p> <p>To enable a near instant change of fan speed when the CPU usage drops, try:<br /> # echo "ondemand" &gt; /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor<br /> # echo "ondemand" &gt; /sys/devices/system/cpu/cpu1/cpufreq/scaling_governor</p> <p>I'm not sure what performance issues this may have. But my machine is quiet again now. I'm researching cpufreqd and trying to userstand how this all works, and will report back!</p> </div></div></div> Sat, 19 Jan 2008 12:45:34 +0000 techuser 19 at http://www.technologicalwanderings.co.uk http://www.technologicalwanderings.co.uk/node/19#comments