On 03/12/12 22:05, Ivan Klymenko wrote:
В Mon, 12 Mar 2012 21:55:21 +0200
Alexander Motin<m...@freebsd.org> пишет:
On 03/12/12 21:33, Ivan Klymenko wrote:
В Mon, 12 Mar 2012 21:15:35 +0200
Alexander Motin<m...@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
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