Intel TurboBoost in practice

Alan Cox alan.l.cox at
Sat Jul 24 17:30:33 UTC 2010

2010/7/24 Alexander Motin <mav at>

> Hi.
> I've make small observations of Intel TurboBoost technology under
> FreeBSD. This technology allows Intel Core i5/i7 CPUs to rise frequency
> of some cores if other cores are idle and power/thermal conditions
> permit. CPU core counted as idle, if it has been put into C3 or deeper
> power state (may reflect ACPI C2/C3 states). So to reach maximal
> effectiveness, some tuning may be needed.

> PPS: I expect even better effect achieved by further reducing interrupt
> rates on idle CPUs.
I'm currently testing a patch that eliminates another 31% of the global TLB
shootdowns for a "buildworld" on an amd64 machine.  So, you can expect
improvement in this area.


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