Improved Intel Turbo Boost status/control

[Alexander Motin]

On 03/12/12 22:05, Ivan Klymenko wrote:
> В Mon, 12 Mar 2012 21:55:21 +0200
> Alexander Motin<mav at FreeBSD.org>  пишет:
>
>> On 03/12/12 21:33, Ivan Klymenko wrote:
>>> В Mon, 12 Mar 2012 21:15:35 +0200
>>> Alexander Motin<mav at FreeBSD.org>   пишет:
>>>> I'd like to note that recent r232793 change to cpufreq(4) in HEAD
>>>> opened simple access to the  Intel Turbo Boost status/control. I've
>>>> found that at least two of my desktop systems (based Nehalem and
>>>> SandyBridge Core i7s) with enabled Intel Turbo Boost in BIOS it is
>>>> not use it by default, unless powerd is enabled. And before this
>>>> change it was difficult to detect/fix.
>>>>
>>>> ACPI reports extra performance level with frequency 1MHz above the
>>>> nominal to control Intel Turbo Boost operation. It is not a bug,
>>>> but feature:
>>>> dev.cpu.0.freq_levels: 2934/106000 2933/95000 2800/82000 ...
>>>> In this case value 2933 means 2.93GHz, but 2934 means 3.2-3.6GHz.
>>>>
>>>> After boot with default settings I see:
>>>> dev.cpu.0.freq: 2933
>>>> , that means Turbo Boost is disabled.
>>>>
>>>> Enabling powerd or just adding to rc.conf
>>>> performance_cpu_freq="HIGH"
>>>> enables Turbo Boost and adds extra 10-20% to the system
>>>> performance.
>>>>
>>>> Turbo Boost operation can be monitored in run-time via the PMC with
>>>> command that prints number or really executed cycles per CPU core:
>>>> pmcstat -s unhalted-core-cycles -w 1
>>>>
>>>
>>> Thank you very much!
>>> performance_cpu_freq="HIGH"
>>> and as this option must be combined with state of the processor C1
>>> C2 C3?
>>> performance_cx_lowest="XX"
>>> economy_cx_lowest="XX"
>>
>> The more CPU cores on package are sleeping and the deeper they are
>> sleeping, the bigger will be boost for remaining active cores.
>> Without using deeper C-states boost is usually quite small (about
>> 100-200MHz for desktop chips). Enabling C-states increases it in few
>> times.
>>
>
> I have a Core i5 c Turbo Boost technology (enabled in BIOS)
> After the following:
> sysctl dev.cpu.0.freq_levels
> dev.cpu.0.freq_levels: 2301/35000 2300/35000 2000/29079 1800/25766 1600/22265 1400/18904 1225/16541 1200/15996 1050/13996 1000/12907 875/11293 800/9956 700/8711 600/7467 500/6222 400/4978 300/3733 200/2489 100/1244
>
> performance_cpu_freq="HIGH">>  /etc/rc.conf
>
> /etc/rc.d/powerd restart
>
> sysctl dev.cpu.0.freq_levels
> dev.cpu.0.freq_levels: 2301/35000 2300/35000 2000/29079 1800/25766 1600/22265 1400/18904 1225/16541 1200/15996 1050/13996 1000/12907 875/11293 800/9956 700/8711 600/7467 500/6222 400/4978 300/3733 200/2489 100/1244
>
> CPU frequency does not rise above 2300 Mhz
>
> What am I doing wrong?

performance_cpu_freq variable handled not by /etc/rc.d/powerd, but 
/etc/rc.d/power_profile.

-- 
Alexander Motin