Forwarding this bug from Ubuntu reporter Vitaly Zawullon Katraev:
http://bugs.launchpad.net/ubuntu/+source/xserver-xorg-video-ati/+bug/748080

[Problem]
ATI card fan is always on with opensource radeon driver

[Original Description]
$ cat /sys/class/drm/card0/device/power_profile
low

When I use the opensource driver for my ATI card the notebook fan is always spinning and temperature of outgoing air from fan is very high, even when I set /sys/class/drm/card0/device/power_profile to low and cpu mode to powersave. With proprietary drivers (fglrx) I set video card performance to "ondemand" (I forgot the exact name of this mode in ATI control center) and cpu mode to ondemand, and the notebook isn't hot, fans are not spinning (if I don't start flash, games or some similar app with high cpu load). So with fglrx I can use the notebook on battery for 1.5 - 2 hours and it's not hot, but with the opensource driver notebook on battery is dead in 50 minutes, the fan is always on, it noise is loud, and the notebook is very hot.

DistroRelease: Ubuntu 11.04
Package: xserver-xorg-video-radeon 1:6.14.0-0ubuntu4
ProcVersionSignature: Ubuntu 2.6.38-7.39-generic 2.6.38
Uname: Linux 2.6.38-7-generic i686
NonfreeKernelModules: wl
Architecture: i386
CompizPlugins: [core,bailer,detection,composite,opengl,imgjpeg,compiztoolbox,decor,snap,move,grid,mousepoll,regex,gnomecompat,winrules,resize,vpswitch,staticswitcher,imgpng,imgsvg,place,text,wall,shift,unitymtgrabhandles,animation,expo,session,workarounds,fade,scale,unityshell]
CompositorRunning: compiz
DRM.card0.DIN.1:
status: disconnected
enabled: disabled
dpms: On
modes:
edid-base64:
DRM.card0.LVDS.1:
status: connected
enabled: enabled
dpms: On
modes: 1280x800 1280x720 1152x768 1024x768 800x600 848x480 720x480 640x480
edid-base64: AP///////wBMo0FIAAAAAAARAQOAGhB4Cof1lFdPjCcnUFQAAAABAQEBAQEBAQEBAQEBAQEBEhsAh1AgEDAQMBMABaMQAAAZAAAADwAAAAAAAAAAACOHAmQAAAAA/gBTQU1TVU5HCiAgICAgAAAA/gAxMjFBVDAyLTAwMQogACs=
DRM.card0.VGA.1:
status: disconnected
enabled: disabled
dpms: On
modes:
edid-base64:
Date: Sat Apr  2 11:22:18 2011
DistUpgraded: Fresh install
DistroCodename: natty
DistroVariant: ubuntu
DkmsStatus: bcmwl, 5.100.82.38+bdcom, 2.6.38-7-generic, i686: installed
GraphicsCard:
ATI Technologies Inc RS780M/RS780MN [Radeon HD 3200 Graphics] [1002:9612] (prog-if 00 [VGA controller])
Subsystem: Hewlett-Packard Company Device [103c:30f1]
InstallationMedia: Ubuntu 11.04 "Natty Narwhal" - Beta 1 i386 (20110329.1)
MachineType: Hewlett-Packard HP Pavilion tx2500 Notebook PC
ProcEnviron:
LANGUAGE=ru_RU:en
LANG=ru_RU.UTF-8ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-2.6.38-7-generic root=UUID=3f65bc34-e565-469c-bde1-e492cfd241ad ro quiet splash vt.handoff=7
Renderer: Unknown
SourcePackage: xserver-xorg-video-ati
UpgradeStatus: No upgrade log present (probably fresh install)
dmi.bios.date: 08/18/2009
dmi.bios.vendor: Hewlett-Packard
dmi.bios.version: F.0F
dmi.board.asset.tag: Base Board Asset Tag
dmi.board.name: 30F1
dmi.board.vendor: Quanta
dmi.board.version: 97.22
dmi.chassis.type: 10
dmi.chassis.vendor: Quanta
dmi.chassis.version: N/A
dmi.modalias: dmi:bvnHewlett-Packard:bvrF.0F:bd08/18/2009:svnHewlett-Packard:pnHPPaviliontx2500NotebookPC:pvrRev1:rvnQuanta:rn30F1:rvr97.22:cvnQuanta:ct10:cvrN/A:
dmi.product.name: HP Pavilion tx2500 Notebook PC
dmi.product.version: Rev 1
dmi.sys.vendor: Hewlett-Packard
version.compiz: compiz 1:0.9.4git20110322-0ubuntu5
version.libdrm2: libdrm2 2.4.23-1ubuntu5
version.libgl1-mesa-glx: libgl1-mesa-glx 7.10.1-0ubuntu3
version.xserver-xorg: xserver-xorg 1:7.6~3ubuntu11
version.xserver-xorg-video-ati: xserver-xorg-video-ati 1:6.14.0-0ubuntu4
version.xserver-xorg-video-intel: xserver-xorg-video-intel 2:2.14.0-4ubuntu4
version.xserver-xorg-video-nouveau: xserver-xorg-video-nouveau 1:0.0.16+git20110107+b795ca6e-0ubuntu6