Re: Improved Intel Turbo Boost status/control

From: Ivan Klymenko <fidaj_at_ukr.net>
Date: Mon, 12 Mar 2012 22:05:56 +0200
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?
Received on Mon Mar 12 2012 - 19:06:07 UTC

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