Laptop CPU overheating in Fedora, temperature +30 celsius higher than in Windows

[Pasi Kärkkäinen]

On Sun, Jun 12, 2011 at 06:20:55PM +0100, José Matos wrote:
> On Sunday 12 June 2011 16:56:33 Pasi Kärkkäinen wrote:
> > Hello list,
> > 
> > Any tips how to debug why laptop CPU temperature is around 30 degrees
> > celsius higher on Fedora 14 or Fedora 15 compared to Windows 7 ? Both
> > Linux and Windows were idle when measuring..
> > 
> > I tried both Fedora 14 (Linux 2.6.35) and Fedora 15 (Linux 2.6.38).
> > Laptop specs:
> > 	- HP Elitebook 8530p.
> > 	- CPU: Mobile Intel Core 2 Duo T9600 (Penryn).
> > 
> > Results:
> > 	- Windows: CPU is 57 - 65 celsius when idle.
> > 	- Fedora/Linux: CPU is 85 - 95 celsius when idle.
> > 
> > The laptop definitely feels much more hot when in Linux
> > and sometimes shuts down with thermal overheating warning.
> > That overheating problem never happens in Windows.
> > 
> > Checking "powertop" in Linux shows the CPU is mostly running
> > with the lowest MHz available. Not much "idle" time though..
> > 
> > I was using "Core Temp" in Windows and /sys ACPI interface in Linux:
> > 
> > # cat /sys/bus/acpi/devices/LNXTHERM\:03/thermal_zone/temp
> > 86000
> > 
> > # cat /sys/bus/acpi/devices/LNXTHERM\:03/path
> > \_TZ_.CPUZ
> > 
> > "acpi -t" also shows the same CPU temperature.
> > Fedora 15 Linux 2.6.38 dmesg here:
> > http://pasik.reaktio.net/fedora/f15/cputemp/dmesg-laptop-f15.txt
> > 
> > 
> > Any ideas how to track what's causing that? All suggestions welcome!
> > Thanks,
> > 
> > -- Pasi
> 
> What is the graphics card?
> 

It's ATI radeon RV635. Do you have the same graphics card? 


> I am running this from a laptop of the same model and I see:
> 
> $ sensors
> acpitz-virtual-0
> Adapter: Virtual device
> temp1:        +30.0°C  (crit = +115.0°C)
> temp2:        +50.0°C  (crit = +105.0°C)
> temp3:        +26.6°C  (crit = +112.0°C)
> temp4:        +58.0°C  (crit = +112.0°C)
> temp5:        +46.0°C  (crit = +90.0°C)
> temp6:        +16.0°C  (crit = +112.0°C)
> 

So your CPU temp is what it should be.. 

> radeon-pci-0100
> Adapter: PCI adapter
> temp1:        +58.0°C  
> 
> coretemp-isa-0000
> Adapter: ISA adapter
> Core 0:       +51.0°C  (high = +105.0°C, crit = +105.0°C)
> 
> coretemp-isa-0001
> Adapter: ISA adapter
> Core 1:       +50.0°C  (high = +105.0°C, crit = +105.0°C)
> 
> The only thing I have done in order to cool down graphics card was to run:
> 
> # echo mid > /sys/class/drm/card0/device/power_profile
> 

Oh, I wasn't aware of this. I'll try and see if that makes a difference.


> instead of the default value auto (that alternates between mid (middle) and 
> high) for the graphics card.
> 
> Definitivily I saw an improvement between F14 and F15.
> 
> Running the graphics card power profile as low brings the temperature even 
> lower (at the expense of some slower window updates).
> 
> FWIW I never had a problem with overheating.
> 

Ok, good to know.

> Regarding the comparison with windows (win.. what?) ;-) this computer came 
> with freedos installed so no such luck here. :-D
> 

:)

Thanks for the reply!

-- Pasi