System extremely slow under light load

[Bartosz Fabianowski]

> Did you try to set OS override to any of the values, recognized by
> your BIOS, with most interesting being  "Windows 2001 SP2", "Windows
> 2006" and "Windows 2009".

Yes, I tried this a while ago, before messing with the DSDT. I figured 
it was unlikely that Dell shipped a DSDT which leads to 0°C readings 
under Windows. Alas, no OS override seemed to change anything. The CPU 
was running just as hot and the temperature reported by ACPI remained 
0°C. Now that I have tried Linux, I can confirm that there, too, the 
temperature is 0°C. The DSDT is completely broken.

>  Additionally, could you, by any chance, replace _TMP method in TZ01
> with the snippet below and let me know what the result is:

I am running with that change right now. It seems to have the same 
effect as my own fixes: hw.acpi.thermal.tz1.temperature works and 
returns a temperature that agrees with dev.cpu.X.temperature. No other 
obvious changes. All temperatures are still in the same ranges.

- Bartosz