mersenneforum.org

mersenneforum.org (https://www.mersenneforum.org/index.php)
-   PrimeNet (https://www.mersenneforum.org/forumdisplay.php?f=11)
-   -   LINUX mprime does not switch speedstep off (https://www.mersenneforum.org/showthread.php?t=10942)

graysky 2008-11-09 12:14

LINUX mprime does not switch speedstep off
 
This may be by design, but the latest 64-bit version of mprime doesn't run with a nice level high enough to trigger the flip of speedstep from low to full.

For example, my X3360 speedsteps down to 6x333 when idle and 8.5x333 which under load - except when mprime is loading it! It doesn't matter which of the three torture tests I run, all four cores get loaded @ 100 % but at 70 % power (6x333). I have to manually tweak the nice level from -19 to 0 to invoke speedstep applying full power to the machine.

Just wanted to report this behavior even if it's known and by design :)

S00113 2008-11-09 14:30

You can adjust the nice value via the Prioryty setting in prime.txt. Priority 1 corresponds to nice 19, priority 10 is 0.

The point of SeedStep is to save power, and the only time SpeedStep saves power is when a process uses 100% CPU. Power consumption while idling is far below power consumption while working at any frequency, and does not depend on CPU frequency as most of the CPU is switched off. It is best to leave the frequenzy at max to make short bursts of activity complete as fast as possible, staying idle most of the time. Speedstep s only useful when a backgrond task like mprime is using 100% CPU all the time. In that case you save some power by lowering the CPU frequency, but get less work done as well.

mdettweiler 2008-11-09 19:27

[quote=graysky;148485]This may be by design, but the latest 64-bit version of mprime doesn't run with a nice level high enough to trigger the flip of speedstep from low to full.

For example, my X3360 speedsteps down to 6x333 when idle and 8.5x333 which under load - except when mprime is loading it! It doesn't matter which of the three torture tests I run, all four cores get loaded @ 100 % but at 70 % power (6x333). I have to manually tweak the nice level from -19 to 0 to invoke speedstep applying full power to the machine.

Just wanted to report this behavior even if it's known and by design :)[/quote]
This is an issue that crops up with many different varieties of lowest-priority/computationally-intensive apps, such as Prime95, LLR, etc., on many varieties of Linux, both 32-bit and 64-bit (though it tends to happen more on 64-bit systems.) One way to fix this is to use the "CPU Frequency Scaling Monitor" taskbar applet to change the CPU scaling governor to "Performance" (though this only works on GNOME--though I'm sure KDE and others have a similar applet available), though unfortunately that requires you to "re-fix" the problem each time you restart. A more permanent solution is to add the following to /etc/rc.local:

[I]echo performance > /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor[/I]

If you have a multi-core/multi-CPU system, you'll need to add more such lines, one for each CPU/core, changing "cpu0" to the respective value each time.

Hope this helps! :smile:

graysky 2008-11-09 21:05

Dunno... the Gnome app doesn't allow me control at all...

[img]http://img362.imageshack.us/img362/9416/37351629ge6.gif[/img]

mdettweiler 2008-11-09 21:09

[quote=graysky;148550]Dunno... the Gnome app doesn't allow me control at all...

[img]http://img362.imageshack.us/img362/9416/37351629ge6.gif[/img][/quote]
First of all, which distro are you using? If it's Debian, Ubuntu, or any other distro that uses the Debian package managing system, the following will fix this:

-Open a terminal.
-Run the command "sudo dpkg-reconfigure gnome-applets"
-Answer yes to the question asking whether to allow cpufreq-selector to run with root privileges.

graysky 2008-11-09 21:31

[QUOTE=mdettweiler;148551]First of all, which distro are you using? If it's Debian, Ubuntu, or any other distro that uses the Debian package managing system, the following will fix this:

-Open a terminal.
-Run the command "sudo dpkg-reconfigure gnome-applets"
-Answer yes to the question asking whether to allow cpufreq-selector to run with root privileges.[/QUOTE]

I'm running lenny amd64. Very cool, now I can adjust the properties.

Thanks!

henryzz 2008-11-15 18:08

[quote=graysky;148485]This may be by design, but the latest 64-bit version of mprime doesn't run with a nice level high enough to trigger the flip of speedstep from low to full.

For example, my X3360 speedsteps down to 6x333 when idle and 8.5x333 which under load - except when mprime is loading it! It doesn't matter which of the three torture tests I run, all four cores get loaded @ 100 % but at 70 % power (6x333). I have to manually tweak the nice level from -19 to 0 to invoke speedstep applying full power to the machine.

Just wanted to report this behavior even if it's known and by design :)[/quote]
you should be able to turn speedstep off in the bios


All times are UTC. The time now is 04:13.

Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2021, Jelsoft Enterprises Ltd.