PDA

View Full Version : Please, help me with CPU throttling (P III Coppermine)



premudriy
18th August 2008, 07:28 PM
Hello, people!


Please, someone help me get CPU throttling to work. I've tried numerous posts suggestions, but was unable make it work. I must be missing some steps.

What I already did:

I've installed Frequency Scaling monitor and "cpufreq-utils."
I've enabled cpuspeed service on all runlevels, though it doesn't start even when I issue "service cpuspeed start"

Here's the output of "more /proc/cpuinfo:

[root@localhost ~]# more /proc/cpuinfo
processor : 0
vendor_id : GenuineIntel
cpu family : 6
model : 8
model name : Pentium III (Coppermine)
stepping : 6
cpu MHz : 697.410
cache size : 256 KB
fdiv_bug : no
hlt_bug : no
f00f_bug : no
coma_bug : no
fpu : yes
fpu_exception : yes
cpuid level : 2
wp : yes
flags : fpu vme de pse tsc msr pae mce cx8 mtrr pge mca cmov pat pse36
mmx fxsr sse up
bogomips : 1396.04
clflush size : 32

And here's the "acpitool -c" output:

[root@localhost ~]# acpitool -c
CPU type : Pentium III (Coppermine)
CPU speed : 697.410 MHz
Cache size : 256 KB
Bogomips : 1396.04
Processor ID : 0
Bus mastering control : yes
Power management : yes
Throttling control : yes
Limit interface : yes
Active C-state : C0
C-states (incl. C0) : 4
Usage of state C1 : 10 (0.0 %)
Usage of state C2 : 31485 (36.1 %)
Usage of state C3 : 55725 (63.9 %)
T-state count : 8
Active T-state : T0
It seems from the above output that CPU must support frequency scaling.

Also, when I add Frequency Scalling monitor applet to panel in Gnome it says that my CPU either not supporting throttling or system is misconfigured, and latter must be the case


My laptop is Compaq Evo N400c.


Thank you beforehand!

forkbomb
19th August 2008, 01:03 AM
Just a thought...

It might be that the cpuspeed daemon or the Linux kernel itself disallows throttling a CPU with that low a native clock frequency anyway.

Two cents - and I know it sounds like a copout - I doubt that if you get the frequency scaling working properly that your processor will scale back very often anyway. 700mhz is about the minimum for running Fedora - it's just borderline. I'd personally probably not even bother running Fedora on anything less than a 1ghz (depending on memory on the machine) - not with a GUI, at least. But I'm an impatient dude. I just don't think the on-the-fly throttling would be invoked very often. On the other hand, my laptop is usually throttled back to 800mhz and runs fine, though on the first hand I'm running a Pentium M and not a Pentium III.
That said..

I've enabled cpuspeed service on all runlevels, though it doesn't start even when I issue "service cpuspeed start"
Any thoughts as to why? Any error messages? Any indication in log files or the kernel ring buffer?

Also, would there be any settings in your BIOS related to frequency scaling? Maybe your BIOS is disallowing it.

premudriy
19th August 2008, 02:51 AM
Hi tjvanwyk,

Even though you're right about 700MHz min. to run Fedora, I still very interested in CPU scaling to 500MHz while I read web pages.

I didn't get any errors from trying to start cpuspeed daemon. When I issue "service cpuspeed start" there's nothing being outputted, which would normally happen if command went successfully, but daemon status reports that it's not running.

The BIOS in this laptop is very primitive - it will only let me to adjust very basic settings like boot order, numlock key, etc. The only setting that is related CPU scaling is called "Automatic SpeedStep Technology." The odd thing is that if I disable that setting, then CPU frequency drops to 499MHz and stays there no matter what - even in Windows. I have to make it enabled in order to get 700MHz of this piece of work.

What about those "governors" I've read about. I'm kind of confused: are they the drivers for specific CPUs or what? Should I load one? Which one then, and how?

I didn't change any major system settings since Fedora install and I've read that P III Coppermine is supposedly supported by default in Fedora. I have no idea why it doesn't work by default in my laptop.

Any idea as to what else I should try to make it working? Maybe you can tell me what commands output I should post that could help you determine what is wrong?

Thanks

marcrblevins
19th August 2008, 07:25 AM
Are you saying you have a 800 mhz PIII processor and Windows dumbgrade it to 499mhz? I believe this is Intel Stepside program(can't rember if that is the correct name). If it idling, nothing happening, it conserve energy for the battery live. Its utimate goal was the battery life. If you are running the lappy with the cord plug in, then disable the Stepside program.
On the linux point of view, just turn off the cpufreq or cpuspeed if you are not using the battery thingy.

premudriy
19th August 2008, 02:53 PM
Are you saying you have a 800 mhz PIII processor and Windows dumbgrade it to 499mhz? I believe this is Intel Stepside program(can't rember if that is the correct name). If it idling, nothing happening, it conserve energy for the battery live. Its utimate goal was the battery life. If you are running the lappy with the cord plug in, then disable the Stepside program.
On the linux point of view, just turn off the cpufreq or cpuspeed if you are not using the battery thingy.


No, I'm saying that there's an option in BIOS called auto speedstep technology, and if I disable it, then CPU frequency goes down to 499MHz in Windows, Fedora, and any other OS on that matter.

If it's Enabled, then Windows can control CPU throttling just fine, but Fedora can't for some reason.

My goal is to make Fedora be able to throttle CPU, so I can drop it down as possible when I read web pages through college wifi, while on battery power.

premudriy
19th August 2008, 03:43 PM
For those who already have CPU throttling working and have some experience in this:

Does CPU throttling normally work out of the box, by default, or does it REQUIRE some work on every system?