Ubuntu – How to get turbo boost working

11.04 runs the 2.6.38 kernel which is supposed to work well with Sandy Bridge CPUs.

You can open a terminal and run grep MHz /proc/cpuinfo. Then open a second terminal tab and run a loop like while :; do :; done. In the first terminal, run grep MHz /proc/cpuinfo again. You should see one of the cores has a higher frequency now:

$ grep MHz /proc/cpuinfo 
cpu MHz         : 1600.000
cpu MHz         : 1600.000
cpu MHz         : 1600.000
cpu MHz         : 1600.000
cpu MHz         : 1600.000
cpu MHz         : 3701.000
cpu MHz         : 1600.000
cpu MHz         : 1600.000

You can also try powertop and turbostat from the linux-tools-common package (run sudo modprobe msr before sudo turbostat). The Git version of i7z is supposed to work for Sandy Bridge (and it works for me with a desktop i7).

You could set the max CPU frequencies to a setting just under the turbo boost - attached is the code I use in rc.local

echo 1 > /sys/module/processor/parameters/ignore_ppc

for x in /sys/devices/system/cpu/cpu[0-3]/cpufreq/;do 
  echo 2501000 > $x/scaling_max_freq
done

In my system the speed of 250100 is a turbo speed, non-turbo being 2500000

Charles Green