i5 2500 Intel Turbo Boost not working

[dashbad]

I have an i5 2500 running in an Intel H67 chipset mobo (Asus P8H67-i) on a stock install of Fedora 16.

Intel turbo boost is enabled in the Bios and I've discovered i7z which is telling me that turboboost is enabled and that the max multipliers for my CPU should be 34,35,36,37 however when I stress the CPU (using Stress) the multiplier never goes higher than 34 for all cores.

Does anyone know why this could be? Is this a limitation of fedora?

Thanks in advance

[stevea]

What does powertop report ?

[Adunaic]

Originally Posted by dashbad

I have an i5 2500 running in an Intel H67 chipset mobo (Asus P8H67-i) on a stock install of Fedora 16.

Intel turbo boost is enabled in the Bios and I've discovered i7z which is telling me that turboboost is enabled and that the max multipliers for my CPU should be 34,35,36,37 however when I stress the CPU (using Stress) the multiplier never goes higher than 34 for all cores.

Does anyone know why this could be? Is this a limitation of fedora?

Thanks in advance

You say for all cores. I thought that the boost only kicked in when cores were not being used -where the usage should be 8, 4, 2, or 1 which correspond to boosts of 34, 35, 36 and 37.

[stevea]

Originally Posted by Adunaic

You say for all cores. I thought that the boost only kicked in when cores were not being used -where the usage should be 8, 4, 2, or 1 which correspond to boosts of 34, 35, 36 and 37.

Bingo - good catch

http://www.intel.com/support/process.../CS-032278.htm

[dashbad]

Originally Posted by stevea

Bingo - good catch

http://www.intel.com/support/process.../CS-032278.htm

Yes - I feel sheepish now. This is expected behavior.


Thanks for clarifying

[DrHappyAngry]

There's a tool called turbostat that will accurately determine the speed of each core. In /proc/cpuinfo, the cores will only show at most 1mhz above their default clocks in turbo mode.

http://mirror.linux.org.au/linux/ker...est/turbostat/