Getting CPU over 800MHz in Fedora

[MDE]

I installed Fedora Core 3 on my eMachines M6805 (Mobile A64 3000+) and the CPU is stuck at 800MHz. I tried installing this program which seems like it would fix the issue but I can't seem to get it to ramp up the CPU speed with a load. If I run "cat /proc/cpuinfo" from time to time while the GUI finishes loading I see the CPU at 800, 1.6, and 1.8, but when everything is loaded up and I start Folding@Home (which does use 100% of the CPU), it settles back down to 800MHz. Basically, how can I get it to dynamically throttle the CPU speed with a workload?

 

[Nothinman]

If you're going to run F@H why not just disable all of the cpufreq stuff since the CPU will be at 100% all of the time anyway?

 

[MDE]

Originally posted by: Nothinman
If you're going to run F@H why not just disable all of the cpufreq stuff since the CPU will be at 100% all of the time anyway?

Because I'd like it to adjust while on battery power.

 

[Nothinman]

What are you using to do the adjustments? If you set the governer to userspace it'll be at full speed unless something like powernowd throttles it back down, so just stop powernowd and it'll be at 100%.

 

[MDE]

Originally posted by: Nothinman
What are you using to do the adjustments? If you set the governer to userspace it'll be at full speed unless something like powernowd throttles it back down, so just stop powernowd and it'll be at 100%.

1) Nothing right now (that I know of)
2) How would I do that?
3) PowerNow can't be turned off AFAIK. There's no BIOS setting, and I still want to to work, just not on AC power and not while the CPU is at 100% load.

 

[Nothinman]

1) Either something is running or you're set to use ondemand kernel governer. To see what governer is in use look at /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor
2) If one isn't running install one, there's a few cpufreq controlling daemons out there.
3) powernowd is a userspace daemon for controlling cpufreq.

You can setup ACPI scripts to stop and start the service when the plug is pulled and plugged in or you can tell powernowd to include 'nice' processes in it's calculations which should make it not touch the cpufreq while F@H is running.

 

[InlineFive]

Turn off Cool'n'Quiet and disable PowerNow!

 

[MDE]

Originally posted by: PorBleemo
Turn off Cool'n'Quiet and disable PowerNow!

See #3 in my last post. There's no BIOS setting for PowerNow and mobile chips don't have Cool n Quiet.

Nothinman, I'll give your suggestions a whirl later on tonight.

 

[MDE]

Powernowd seems to have fixed the issue. Thanks!

 

[drag]

I kinda like the cpu freq management in Linux now.

Powernowd is, if I remember correctly, and pure userspace program.. no hooks into kernel space.

If you want, and depending on which version of fedora your using, you can control the cpu speed manually thru the sysfs interface, which is how powernowd does it (I beleive).

To access the sysfs stuff you just have to go to /sys directory. It's full of 'logical' files that represent different information that is aviable for you to use. It's like /proc/ pretty much, but they want it to be something specificly designed to expose kernel stuff to userspace programs. Other things like 'HAL' and udev use it nowadays.

Well the specific directory, if I remember correctly (it's a bit fuzzy), is:
/sys/devices/system/cpu/cpu0/cpufreq/

You can go in their and see the different governers you have avaible and current frequency and such.

You can tell the kernel what specific cpu speed you want, if the hardware supports it and your using the userspace governer, by echo'ng the speed in hz you want... Some chipsets only support certain ranges or certain frequencies. So if you want a specific cpu, like the slowest setting for longest battery life, you can set it. (after you disable the powernowd deamon, of course)

something like:
echo -n 200000 > /sys/devices/system/cpu/cpu0/cpufreq/scaling_setspeed

I found more info here:
http://www.thinkwiki.org/How_to_make_use_of_Dynamic_Frequency_Scaling

Kinda neat.