Ubuntu
linux package

  1. Bug #818830
  2. Comment #3

Comment 3 for bug 818830

Revision history for this message
Steven Keys (steevven1) wrote : Re: Sandy Bridge serious power regression from kernel 3.0.0-6 to 3.0.0-7 (30% more power at idle)

I am experiencing this same thing, but without an apparent workaround. After upgrading from kernel 2.6.38 to 3.0.0-0300, I saw a DRAMATIC increase in power usage on my Sandy Bridge laptop. I then upgraded to 3.1 and saw no improvement. Trying kernel parameter i915.i915_enable_rc6=1 made no difference whatsoever for me.

I am on a ThinkPad X220 with an Intel(R) Core(TM) i7-2620M CPU @ 2.70GHz.

I documented the symptoms of the problem at http://ubuntuforums.org/showthread.php?t=1822629

The bottom line of that thread is that powertop shows a HUGE number of wakeups from "[Rescheduling interrupts] <kernel IPI>" with the 3-series kernels and no such wakeups with older kernels.