Comment 308 for bug 370173

Hi all,

How many of you are experiencing this meltdown problem on a laptop with AMD/ATI graphics and the radeon or fglrx driver?

Long story short: the following steps have finally fixed it for me (9.10 beta, HP EliteBook 8530p with Intel Core 2 Duo and "ATI Technologies Inc Mobility Radeon HD 3650"):
 - install the xorg-driver-fglrx package manually (in Kubuntu the restricted drivers thing won't work), probably you're running that driver already
 - remove or rename /etc/X11/xorg.conf
 - run "sudo aticonfig --initial" (writes a new xorg.conf, and if I'd reboot my fresh 9.10 install now, I'd just get a blank screen instead of kdm)
 - the fix: "sudo aticonfig --acpi-services=off"

This does NOT change the newly written /etc/X11/xorg.conf file, but now I didn't get a blank screen after rebooting AND the heat issue is a thing of the past! Well, in my case at least.

Long story:
I've wrestled with this incredible heat problem since 9.04 came out and reverted back to 8.10 in despair. Symptoms were:
 - the CPU fan always kept running at high speed, without any system load whatsoever, and with the CPU power saving active ("ondemand" CPU governor)
 - the air being blown out was always hot to really hot
 - happens both in X as on the console with xorg not running
 - powertop proves that the CPU really isn't doing much at all (97% of the time in low power state)
 - reboot into Windows XP or Ubuntu 8.10 and everything is back to normal

Now, on to the interesting stuff: the fact that my CPU was idling all the time always made me believe that the video chip was doing weird stuff (CPU + video share the same heatsink & fan by the way). Today I wanted to see if this was fixed in 9.10 beta, but the installation CD turned my laptop into an oven and after installation it appeared that the issue hadn't improved over 9.04. It didn't look good using the default radeon driver.

Next step: try fglrx of course. I did, and after rebooting X just crashed while loading (blank screen). So I started googling around and came across this bug: https://bugs.launchpad.net/ubuntu/+source/fglrx-installer/+bug/314600 titled "[HD 3650] fglrx versions newer than 8.543 cause system hang and panic". One of the participants mentioned that his temps were back to normal so I immediately did the same steps he had done.

Temps before:

$ sudo acpi -t
Thermal 0: ok, 16.0 degrees C
Thermal 1: ok, 50.0 degrees C
Thermal 2: ok, 64.0 degrees C
Thermal 3: ok, 29.6 degrees C
Thermal 4: ok, 63.0 degrees C
Thermal 5: ok, 30.0 degrees C

Temps now:

$ sudo acpi -t
Thermal 0: ok, 16.0 degrees C
Thermal 1: ok, 36.0 degrees C
Thermal 2: ok, 45.0 degrees C
Thermal 3: ok, 27.6 degrees C
Thermal 4: ok, 47.0 degrees C
Thermal 5: ok, 30.0 degrees C

I suspect that "Thermal 1" is the GFX chip, which is causing so much additional heat that it makes the CPU cores (2 and 4?) a lot hotter as well.

I'm happy! I hope at least some of you have a similar hardware combination and can now start using Ubuntu's latest and greatest.

Still, it's a fix, not a solution, as it's still unclear to me what the cause really is. The --acpi-services=off switch obviously disables something which makes power consumption of the video card skyrocket. I didn't retest the radeon driver now.

Greetings,

Pascal