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 Nehalem CPUs.


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

  • 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 . . . – gregghz 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
  • 7
    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. – Run CMD Jul 24 '14 at 6:06

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.


Accepted top voted answer doesn't always work

As the second top voted answer pointed out, the top voted and accepted answer sometimes shows the maximum regular frequency.

Alternate CLI methods

Below you can see frequencies for CPU Number 0. To see all CPU's replace 0 with *. The frequency is expressed in MHz with three decimal places. So 1000000 = 1000 MHz = 1 GHz. This Intel Skylake processor is rated to 2.6 GHz or 3.5 GHz with Turbo Boost enabled.

Minimum frequency 800 MHz

$ cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_min_freq

Maximum frequency 3500 MHz (3.5 GHz)

$ cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_max_freq

Current frequency 1027.669 MHz (1.028 GHz)

$ cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_cur_freq

CPU 0 to 7 Frequency when YouTube loads up

$ cat /sys/devices/system/cpu/cpu*/cpufreq/scaling_cur_freq

4 out of 8 processors are in turbo mode (above 2.6 GHz)

CPU 0 to 7 Frequency when YouTube paused

$ cat /sys/devices/system/cpu/cpu*/cpufreq/scaling_cur_freq

All processors are at minimum speed of 800 MHz even though Chrome is running on two screens with 11 tabs open but YouTube paused.

Is Intel Turbo Boost enabled?

Using the terminal you can check if Turbo Boost feature is enabled:

$ cat /sys/devices/system/cpu/intel_pstate/no_turbo

This is a double negative; when "no turbo" is off (=0) then Turbo Boost is on.

To disable Turbo Boost use sudo powers and set the switch no_turbo to 1:

$ echo "1" | sudo tee /sys/devices/system/cpu/intel_pstate/no_turbo

The returned 1 indicates turbo is now off.

Alternate GUI method using Conky

Other answers mention alternate methods to the basic CLI (Command Line Interface). I like to use Conky to do this. In the example below the Skylake CPU has a regular frequency from 800 MHz to 2600 Mhz. With turbo boost enabled the frequency can jump to 3500 MHz under heavy load.

The .gif sample below starts out by showing frequency fluctuating around 3100 MHz under heavy load when grep is running on the whole file system. Then the command is issued:

$ echo "1" | sudo tee /sys/devices/system/cpu/intel_pstate/no_turbo

...to shut off turbo boost. Speed drops to fixed speed of 2600 MHz which is the regular maximum speed without turbo.

Then the turbo command is reversed:

$ echo "0" | sudo tee /sys/devices/system/cpu/intel_pstate/no_turbo

...to turn turbo back on and speed jumps above 2600 MHz and fluctuates around 3100 to 3200 MHz again.

Toggle turbo boost

Notice how quickly temperature jumps 10 degrees when Turbo is turned on

  • What part of the Conky gif shows turboboost? – muru Jan 3 '18 at 13:39
  • @muru I should fire up the old laptop and generate a new .gif under heavy load because on the Ivy Bridge CPU turbo engages after 2.4 GHz (2400 MHz). Anyway we assume the conky creator knows his processor speed min, max at non-turbo and turbo max. Then s/he can simply glance at the MHz readout to know if turbo is working or not. – WinEunuuchs2Unix Jan 3 '18 at 23:26
  • Yes, you should. – muru Jan 4 '18 at 3:04
  • On my server running RHEL-6.6 there is no /sys/devices/system/cpu/intel_pstate/no_turbo. The CPUs are Xeon E5-2690, which should have the Boost technology... Is my kernel (2.6.32) too old? – Mikhail T. Jul 25 '18 at 18:51
  • @MikhailT. I'm not sure. I read your specs and it's based on Sandy Bridge which is second generation. My Ivy Bridge was third generation and definitely had the Turbo Boost setup as detailed above. My current laptop is sixth generation (Skylake) and adheres to directories above. Tthey've just released eighth generation (Coffee Lake I think) but haven't looked into that yet. At work we have REHL and one day it crashed to a shell prompt and I discovered the kernel version was 2.6.512 or something like that. I'm afraid I don't know enough to answer your question. – WinEunuuchs2Unix Jul 26 '18 at 0:25

To install turbostat you need to run:

$ sudo apt-get install linux-tools-common linux-tools-generic

(apparently I lack reputation to add this as a comment to @david-gardner post)


cpupower is a collection of tools to examine and tune power saving related features of your processor. cpupower frequency-info can help to get the required info.

Sample output:

# cpupower frequency-info
analyzing CPU 0:
  driver: intel_pstate
  current CPU frequency is 2.80 GHz (asserted by call to hardware).
  boost state support:
    Supported: yes
    Active: yes
    3000 MHz max turbo 4 active cores
    3000 MHz max turbo 3 active cores
    3100 MHz max turbo 2 active cores
    3100 MHz max turbo 1 active cores

boost state - active confirms what you looking for.

Man page: https://linux.die.net/man/1/cpupower

PS: I know its an old thread but thought this answer is appropriate here and can help someone.


For me everything was set properly so none of the answers were applicable. After wasting a couple of days I found out that my CPU governor was set to powersave and would never go above the base frequency. Had to switch it to performance

Here is how to fix it

sudo cpupower frequency-set -g performance

You will need to install cpupower first

sudo apt-get install linux-tools-common linux-tools-generic

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