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Old 2008-11-09, 19:27   #3
A Sunny Moo
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Aug 2007

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Originally Posted by graysky View Post
This may be by design, but the latest 64-bit version of mprime doesn't run with a nice level high enough to trigger the flip of speedstep from low to full.

For example, my X3360 speedsteps down to 6x333 when idle and 8.5x333 which under load - except when mprime is loading it! It doesn't matter which of the three torture tests I run, all four cores get loaded @ 100 % but at 70 % power (6x333). I have to manually tweak the nice level from -19 to 0 to invoke speedstep applying full power to the machine.

Just wanted to report this behavior even if it's known and by design :)
This is an issue that crops up with many different varieties of lowest-priority/computationally-intensive apps, such as Prime95, LLR, etc., on many varieties of Linux, both 32-bit and 64-bit (though it tends to happen more on 64-bit systems.) One way to fix this is to use the "CPU Frequency Scaling Monitor" taskbar applet to change the CPU scaling governor to "Performance" (though this only works on GNOME--though I'm sure KDE and others have a similar applet available), though unfortunately that requires you to "re-fix" the problem each time you restart. A more permanent solution is to add the following to /etc/rc.local:

echo performance > /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor

If you have a multi-core/multi-CPU system, you'll need to add more such lines, one for each CPU/core, changing "cpu0" to the respective value each time.

Hope this helps!
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