[ltp] t42 archlinux fan noise

Arian Kuschki linux-thinkpad@linux-thinkpad.org
Wed, 28 Oct 2009 15:38:02 +0100


Contrary to what I said, enabling laptop-mode and cpufreq alone did not 
have as strong an effect as I had first assumed. There seems to be an 
small positive effect though.

>You should also use hpet=force in /boot/grub/menu.lst which helps keeping the
>CPU idle.

The thinkwiki says to use lspci to check for an ICH5 chipset. According 
to the wiki

>The ICH4 does have an HPET, but it is disabled for a good reason: Intel 
>didn't test/validade it! Use of the ICH4 HPET is not recommended

a ~$ lspci | grep -i intel
00:00.0 Host bridge: Intel Corporation 82855PM Processor to I/O Controller (rev 03)
00:01.0 PCI bridge: Intel Corporation 82855PM Processor to AGP Controller (rev 03)
00:1d.0 USB Controller: Intel Corporation 82801DB/DBL/DBM (ICH4/ICH4-L/ICH4-M) USB UHCI Controller #1 (rev 01)
00:1d.1 USB Controller: Intel Corporation 82801DB/DBL/DBM (ICH4/ICH4-L/ICH4-M) USB UHCI Controller #2 (rev 01)
00:1d.2 USB Controller: Intel Corporation 82801DB/DBL/DBM (ICH4/ICH4-L/ICH4-M) USB UHCI Controller #3 (rev 01)
00:1d.7 USB Controller: Intel Corporation 82801DB/DBM (ICH4/ICH4-M) USB2 EHCI Controller (rev 01)
00:1e.0 PCI bridge: Intel Corporation 82801 Mobile PCI Bridge (rev 81)
00:1f.0 ISA bridge: Intel Corporation 82801DBM (ICH4-M) LPC Interface Bridge (rev 01)
00:1f.1 IDE interface: Intel Corporation 82801DBM (ICH4-M) IDE Controller (rev 01)
00:1f.3 SMBus: Intel Corporation 82801DB/DBL/DBM (ICH4/ICH4-L/ICH4-M) SMBus Controller (rev 01)
00:1f.5 Multimedia audio controller: Intel Corporation 82801DB/DBL/DBM (ICH4/ICH4-L/ICH4-M) AC'97 Audio Controller (rev 01)
00:1f.6 Modem: Intel Corporation 82801DB/DBL/DBM (ICH4/ICH4-L/ICH4-M) AC'97 Modem Controller (rev 01)
02:01.0 Ethernet controller: Intel Corporation 82540EP Gigabit Ethernet Controller (Mobile) (rev 03)
02:02.0 Network controller: Intel Corporation PRO/Wireless LAN 2100 3B Mini PCI Adapter (rev 04)

It does not specify anything for the processor, but several other 
components seem to be ICH4. I assume this means I should not try 
hpet=force? Then again a couple of lines further down, it says:

On modern ThinkPads the HPET timer is automatically detected and 
enabled. On certain older machines hpet=force is required such as on the 
following machines:
T30, T40, T40p, T41, T41p, T42

Which one is the right statement then?


> temp4:       +62.0°C

>This is not "idle temperature".  That's your problem.  And I think it 
>is the >GPU, so either archlinux is doing a screwed up job of GPU power 
>management OR you are now keeping it busy, e.g. by using a compositioning opengl 
>window >manager.

I use dwm as my wm which is fairly resource friendly. But setting

Option      "DynamicClocks" "on"

in my xorg.conf seems to have changed my idle temperature for the GPU 
from around 60 to 49-50. The fan is now 3000 when idle, which is audible 
but still very comfortable. It does not compare to the ultra quiet x31, 
but well...

Thank you for pointing me to the high PGU temperature issue, this really 
has decreased the fan noise.

Cheers
Arian