CPU frequence scaling problem, maximum down when cpu warm

jorrit · Tux's lil' helper Joined: 26 Oct 2005 Posts: 128

Hardware specs: Acer Aspire 5024WLMi laptop with AMD64 Turion processor running 64-bits gentoo. powernowd frequency governer is running and appears to work.

I am still struggling with cpu frequency scaling. As it stands now I think cpu frequency scaling is actually working right but I still have the problem that after about half a minute of very intensive cpu work the maximum frequency is brought down from 1800 to 800. I've check out the /proc/acpi/thermal_zone and I discovered that this happens after a certain temperature is reached. However what is weird is that this happens so fast (after 30 seconds of heavy cpu work already) and that on windows I have no such problems. When system is idle I have the following values in thermal_zone:

In thermal zone TSZ0:

jorrit · Tux's lil' helper Joined: 26 Oct 2005 Posts: 128

Please, does nobody have any advice for me on this subject? I really want to solve this problem.

Greetings and thanks,

Ehnvis · Guru Joined: 13 Jun 2006 Posts: 305 Location: /dev/random

Is the fan working as it should? Thats the only thing i can think of, as you should really never reach the temperatures where the system drops to "passive" cpu speed.
_________________
HP NC 4010, Pentium-M 725 1.6GHz w/ 1Gb RAM, 60Gb Hitachi Travelstar.
Running Gentoo-2.6.21-r4 (again as 2.6.22 kernels hogs CPU), all but SD reader works fine.

jorrit · Tux's lil' helper Joined: 26 Oct 2005 Posts: 128

Well I can hear the fan blowing correctly.

I just did a test in windows with a similar long compile. I noticed that windows also brings down the speed to 800 from time to time during that compile but it does that a lot less frequent. i.e. in windows I estimate the speed is at 1800 for about 75% while in linux the speed is only 1800 for about 25%. During that long compiled I also monitored temperature in windows and it reported the following two maximum values during the compile:

- Temperature Sensor 0: 57
- Temperature Sensor 1: 84

I guess sensor 1 corresponds to thermal zone TSZ0 in linux and probably sensor 0 corresponds to thermal zone TZSV but I'm not 100% sure.

So I guess linux seems to throttle down cpu speed a tad too early compared to windows. Any way I can control that thresshold (i.e. set passive to 84 instead of 82)?

Greetings,

Ehnvis · Guru Joined: 13 Jun 2006 Posts: 305 Location: /dev/random

You should be able to manipulate the trip_points (look at /proc/acpi/thermal_zone/<thermal zone>/trip_points).

Not sure how to manipulate it but hopefully someone else does.
_________________
HP NC 4010, Pentium-M 725 1.6GHz w/ 1Gb RAM, 60Gb Hitachi Travelstar.
Running Gentoo-2.6.21-r4 (again as 2.6.22 kernels hogs CPU), all but SD reader works fine.

jorrit · Tux's lil' helper Joined: 26 Oct 2005 Posts: 128

Can someone tell me if these temperatures are actually normal for an AMD64 Turion? To me they look a bit high but this is a brand new laptop and the fan appears to be working. Also it blows harder as soon as the cpu gets warmer. But could there be something else wrong that causes the cpu to get too worm perhaps?

Greetings,

jamapii · l33t Joined: 16 Sep 2004 Posts: 637

I had the same problem, now I use some external fans connected to a laboratory power supply, to make the cpu go faster