Losing CPU performance in Linux

walla

Senior member
Jun 2, 2001
987
0
0
I seem to be loosing CPU performance (in terms of reported clock speed) while using Linux (SUSE 9.1, x86_64). FYI, I've never overclocked or played around with clock speed in BIOS or through jumpers.

This is the order of events
1)I boot up my computer. Post screen correctly identifies AMD64 3200+ at 2.2GHz.
2)Linux boots. Log in as user (not root).
3)CPU is correctly reported at 2.2GHz (using "cat /proc/cpuinfo"). However, load is contantly 100%.
4)Find that process "cupsd" is consuming 99% of CPU (This is an entirely different problem it seems). I believe this has to do with incorrectly configured print settings or something. So I "kill" the process.
5)Computer will beep twice.
6)Reported GHz drops to 1.8GHz until hard reset.

My first inclination is that powersave is down throttling the clock to save power. I have tried to shut it off by using "powersave -f" (as root), however it gives me the warning that it can't access the daemon, and I am not sure that it is even running at all.

I have also give it CPU intensive task to test if the CPU speed would jump up during that period, but it did not seem to.

Does anyone have an idea how I could go about diagnosing this problem? How can i get those 400MHz back?

It may be worth noting that the clock speed is correctly identified in Windows. I feel it must be Linux.
 

mechBgon

Super Moderator<br>Elite Member
Oct 31, 1999
30,699
1
0
What motherboard you got? Maybe there's something funky going on with the Cool 'n Quiet capability (but keep in mind I'm a mad l33t Linux 1d10t :D)
 

walla

Senior member
Jun 2, 2001
987
0
0
My motherboard is chaintech vnf3-250.

I've figured something out. It was definitly the kpowersave/powersaved that was throttling my CPU.

What I did is logged in as root. The "kpowersave" setting was set on "power save", so I set it to "performance" and the CPU jumped back up to 2.2GHz. Logging in as "user" now starts up at 2.2GHz.

Of course now I have the problem where if I want to switch the mode back (through kpowersave in KDE), the machine crashes. And I still don't know why this "cupsd" want to consume the entire CPU. I will have to explore some more to figure this out.