At work I recently got a new Dell Latitude D810 which is going to
replace my trusty 3 year old Inspiron 8100. I've run FC2 and FC4 on my
8100 and have never had any problems. I installed FC4 on the new D810
and everything works just fine ... except that I getting thermal shutdowns.
The D810 is of recent manufacture - the BIOS is A04 (09/30/2005). The
processor is a 1.86Ghz Pentium M with Centrino SpeedStep. SpeedStep
works okay using the userspace or ondemand governors. Part of the
problem may be due to sensors-detect not being able to find any sensors
or i2cdetect to find any i2c buses. No one seems to know what sensor
chips Dell is using in this laptop. I wrote a script to log the CPU
temperature from /proc/acpi/thermal_zone/THM/temperature (I have no idea
what sensor it is reading) and then exercised the CPU with a tiny C
program doing integer addition and multiplication in a tight loop (top
shows 100% user/0% idle) to force the CPU temperature to rise. Shutdown
occurs at 40C. There's no fan sensor data but the cooling fan seems to
running full speed.
Now here's the strange part. If I boot up Knoppix 3.9 Live CD, there is
no problem with thermal shutdown even when exercising the CPU. The
temperature rises steadily to around 53C or 54C and then decreases back
to around 33C and holds steady.
If I boot the Dell hardware diagnostics and run the non-interactive CPU
tests in an infinite loop there is never a thermal problem. It ran
overnight with no problem.
And finally, if I boot the M$ XP PRO that I kept around on a small
partition and exercise the CPU there is no problem with thermal shutdown.
So I'm fairly confident that there is not a problem with the hardware.
But what is different about FC4? Why does my D810 work with Knoppix and
M$ XP but fail with FC4? What am I missing? If there is anyone that
has a D810 with the A04 BIOS and not having this thermal shutdown
problem with FC4, I'd sure like to hear about it and what if anything
you did to avoid this problem.
