Ubuntu – Enable full performance on Sandy Bridge laptop

14.10performancepower-managementsandy-bridge

I have 2nd gen Intel i7 laptop. I use Thermald and tlp for managing battery life (they are great!). However, sometimes I don't care about noise and power consumption, and want the CPU to run at full 3.5GHz. For some reason, this seems impossible to achieve. The fan never runs full speed, and the processor is always throttled down. When I use cpufreq-info I never see more than 2.8GHz (so turbo boost does not work), and the frequency drops down to 800Mhz when the fan starts getting "loud". This is with intel p-state and performance governor. Powersafe governor is even "worse", but that's good as it increases battery life.

Any ideas how to enable "full power"?

Thank you!

Best Answer

Yes, all you have to do is:

first, set tlp "governer" to performance for both ac and batt in your /etc/default/tlp file and while you are there, go ahead and enable turbo boost as well

then, edit /etc/default/grub and insert

intel_pstate=disable

after

GRUB_CMDLINE_LINUX_DEFAULT=

like this example

GRUB_CMDLINE_LINUX_DEFAULT="intel_pstate=disable quiet splash"

execute this command to apply the change to grub

sudo update-grub

then, install indicator-cpufreq

sudo apt-get update
sudo apt-get install indicator-cpufreq

reboot for your changes to take effect.

After you reboot, you will see an icon on your unity panel, click on this icon and you can set the cpu to performance (full), ondemand (only when needed), powersave, or conservative.


Disabling pstate may not be necessary, you can try it on and off to see if there is a difference. Make sure to update grub after making that change.

Also, indicator-cpufreq will not allow changes with pstate on (only with pstate disabled), you will still have to do that manually.

Finally, you can get better numbers from i7z:

sudo apt-get install i7z

and then, run

sudo i7z

Install lm-sensors and run sensors detect:

sudo apt-get install lm-sensors

sudo sensors-detect

Follow the prompts and select yes to everything.


finally, these links may help:

http://www.webupd8.org/2013/09/adobe-flash-player-hardware.html

Not only does this allow hardware acceleration for flash but installs VDPAU and i965

http://www.webupd8.org/2014/01/enable-hardware-acceleration-in-chrome.html

and these more recent benchmarks show a slight advantage from disabling pstate and using performance

http://www.phoronix.com/scan.php?page=article&item=intel_5960x_pstate&num=2