How to enable CPU turbo mode on FreeBSD?

[Bruce Cran]

On Thu, 10 Sep 2009 20:57:32 -0400
Pierre-Luc Drouin <pldrouin at pldrouin.net> wrote:

> Hi,
> 
> I have an overclocked i7 920 CPU for which I have enabled Turbo Mode
> in the BIOS (21x multiplier). The base clock is set at 190 MHz, so
> the CPU frequency with Turbo mode activated should be 3990 MHz.
> However the maximum value FreeBSD amd64 shows for the CPU frequency
> in dmesg and sysctl is 3790 MHz. How can I enable the Turbo Mode?
> 
> CPU: Intel(R) Core(TM) i7 CPU         920  @ 2.67GHz (3790.52-MHz 
> K8-class CPU)
> 
> machdep.acpi_timer_freq: 3579545
> machdep.tsc_freq: 3790522507
> machdep.i8254_freq: 1193182
> dev.cpu.0.freq: 349
> dev.cpu.0.freq_levels: 2793/130000 2443/113750 2094/97500 1745/81250 
> 1396/65000 1047/48750 698/32500 349/16250

You may be able to use the cpuctl kernel module with sysutils/x86info
to see when the CPUs are using Turbo mode. I haven't had any success
yet but I know in Windows the System control panel reported the 2.66GHz
CPU running at 2.83GHz without me doing anything, so I guess FreeBSD
should be doing the same.

-- 
Bruce Cran