[Bug 429036] Re: core i7 i5 (Lynnfield) turbo boost not working

[gian]

I have a Dell Latitude E6410 with i7 processor  (4x Intel(R) Core(TM) i7
CPU M 620 ). I am running Ubuntu 10.04.1 LTS, after reading above (and
also  https://bugzilla.kernel.org/show_bug.cgi?id=15064 )  I updated the
kernel to "Linux 2.6.35-020635rc1-generic (x86_64)", I have a rather
strange behaviour: if I keep my AC power cord pluged in all cores stay
fixed at 1.2Ghz (minimum speed), If I remove the power cord they
"sometimes" (meaning that the behaviour does not seem "deterministic")
they jump to higher speed values (but never to the maximum possible
speed).


this is what I see using Turbostat with power cord IN (while running make on a large program)

 cor CPU   %c0   GHz  TSC   %c1    %c3    %c6   %pc3   %pc6 
            11.54 1.20 2.66  43.67    9.83  34.97   6.01  11.02
   0   0    5.83 1.21 2.66  56.73    5.15  32.30   6.01  11.02
   0   2  30.01 1.20 2.66  32.54    5.15  32.30   6.01  11.02
   2   1    5.75 1.21 2.66  42.11  14.51  37.63   6.01  11.02
   2   3    4.56 1.22 2.66  43.30  14.51  37.63   6.01  11.02
 cor CPU   %c0   GHz  TSC   %c1    %c3    %c6   %pc3   %pc6 
            24.05 1.20 2.66  48.51    8.22  19.22   0.00   0.00
   0   0    6.66 1.20 2.66  70.43    5.25  17.66   0.00   0.00
   0   2  46.43 1.20 2.66  30.66    5.25  17.66   0.00   0.00
   2   1  21.50 1.20 2.66  46.53  11.20  20.78   0.00   0.00
   2   3  21.62 1.20 2.66  46.40  11.20  20.78   0.00   0.00
 cor CPU   %c0   GHz  TSC   %c1    %c3    %c6   %pc3   %pc6 
            23.71 1.20 2.66  46.22    8.76  21.31   0.00   0.00
   0   0    7.08 1.20 2.66  50.27  12.23  30.42   0.00   0.00
   0   2  26.57 1.20 2.66  30.78  12.23  30.42   0.00   0.00
   2   1  35.55 1.20 2.66  46.96    5.29  12.20   0.00   0.00
   2   3  25.63 1.20 2.66  56.88    5.29  12.20   0.00   0.00


and this is what I get with power cord out
 cor CPU   %c0   GHz  TSC   %c1    %c3    %c6   %pc3   %pc6 
            18.82 2.10 2.66  47.81   7.21  26.16   4.90   6.22
   0   0  26.06 2.10 2.66  43.97   8.18  21.79   4.90   6.22
   0   2  28.85 2.10 2.66  41.18   8.18  21.79   4.90   6.22
   2   1    8.88 2.11 2.66  54.34   6.24  30.53   4.90   6.22
   2   3  11.50 2.12 2.66  51.72   6.24  30.53   4.90   6.22
 cor CPU   %c0   GHz  TSC   %c1    %c3    %c6   %pc3   %pc6 
            27.29 2.13 2.66  50.30   3.60  18.81   0.00   0.00
   0   0  16.80 2.13 2.66  83.20   0.00    0.00   0.00   0.00
   0   2  86.23 2.13 2.66  13.77   0.00    0.00   0.00   0.00
   2   1    3.43 2.13 2.66  51.74   7.20  37.62   0.00   0.00
   2   3    2.70 2.13 2.66  52.48   7.20  37.62   0.00   0.00
 cor CPU   %c0   GHz  TSC   %c1    %c3    %c6   %pc3   %pc6 
            19.92 2.12 2.66  49.84   4.25  25.98   0.39   5.11
   0   0  68.50 2.13 2.66  20.93   0.96    9.61   0.39   5.11
   0   2    4.75 2.09 2.66  84.68   0.96    9.61   0.39   5.11
   2   1    3.35 2.10 2.66  46.74   7.54  42.36   0.39   5.11
   2   3    3.10 2.10 2.66  47.00   7.54  42.36   0.39   5.11

It seems to me that there are still some issues with I7 mobile
processors (btw, I also have a NON mobile i7 920 at home that does not
seem to give me any problem with standard Ubuntu 9.10) ....

-- 
core i7 i5 (Lynnfield) turbo boost not working
https://bugs.launchpad.net/bugs/429036
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