Take the 2-minute tour ×
Ask Ubuntu is a question and answer site for Ubuntu users and developers. It's 100% free, no registration required.

I recently purchased a laptop with a sandy bridge CPU that is supposed to have turbo boost. Is turbo boost supported in 11.04? How can I tell if it's working?

I tried this but it seems to only detect nehelam CPUs.

share|improve this question
add comment

2 Answers 2

up vote 13 down vote accepted

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 SVN version of i7z is supposed to work for Sandry Bridge (and it works for me with a desktop i7).

share|improve this answer
    
Thanks for that. It appears that turbo boost is not working for me. I have the 8,1 macbook pro. and it maxes out at 2.7ghz which is the advertised base clock speed, while the turbo boost speed is advertised at 3.4ghz. I'll probably start a new question on this . . . –  greggory.hz May 20 '11 at 23:03
    
I am somewhat confused: using your technique Turbo Boost does not seem to work. However if I use i7z script is tells me that Turbo Boost is enabled. –  n3rd Nov 1 '11 at 18:03
    
@R3s3t, the 3701 really means 3700 with turbo boost enabled, to be activated at the discretion of the motherboard. –  psusi Dec 14 '11 at 14:36
    
This is weird my processor hase a base clock speed of 1.8 GHz with turbo boost up to 2.6 GHz but I this only shows me 800MHZ to 1.8GHz. No wonder Ubuntu feels a bit laggy... :( –  king_julien Jul 25 '13 at 16:49
    
This answer appears to be only partially true. All the info in /proc/ and /sys/device/system/cpu/ is always limited to regular frequencies by design; see kernel.org/doc/Documentation/cpu-freq/boost.txt Also, the CPU Freq Mons rely on this information, so they will not show boosts. But turbostat and other tools will. Special care should be taken for AMD processors with integrated graphics, see askubuntu.com/a/501599/308343 @king_julien Your assumption is probably wrong. –  Class Stacker 34 mins ago
add comment

Use sudo turbostat for this. The output of cat /proc/cpuinfo does not always show the real current CPU frequency but instead the maximum non-turbo frequency even when Turbo Boost is enabled and active.

As stated in elmicha's answer, you'll need to load the msr module with sudo modprobe msr and then run turbostat with sudo turbostat.

share|improve this answer
add comment

Your Answer

 
discard

By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.