Let me share my experience that i posted on 26 Jun 2009 11:26AM on Dell Forums.
Hello everyone, i made some lab tests, as i am now in a phase with support when I should prepare one computer for a send to my Local Dell subsidiary. At this moment i am able to replicate the problem really fast.
HW & Software Setup: Windows 7 RC 32bit, Dell
E6400, P8400, 4GB, 500G Samsung Drive, Speedfan 4.39 Beta 7, WLAN Enabled
Speedfan installation nad config: To run Speedfan you have to right click it>properties and run it in windows xp sp3 compatibility mode (caused by W7), also in configure>options enable Dell support and restart the app. In Speedfan go to Charts and enable Temp4, Temp5, CPU, GPU
To cause stress: I've been using Google Earth, but any video app will do. (Higher the resolution the better - Dual monitor also good...)
Monitoring: Resource Monitor from W7 (to run it just type in Resource Monitor in Vista or W7)
Window setup: Google Earth in the background rotating around the globe (actually moving!). On the left Resource Monitor and on the right Speedfan.
note: TEMP4 TEMPERATURE ALWAYS EQUALS TEMP5, SO I WILL WRITE DOWN ONLY TEMP4!
* AMBIENT TEMPERATURE: 26C (whitepaper allows conditions up to 35C!)
* IDLE: TEMP4=49C, CPU=48C, GPU=48C
* STRESS TEST: TEMPS RISING...
* THROTTLING SLOWDOWN DOWN TO 20% OF CPU ORIGINAL PERFORMANCE : TEMP4 HITS 55C! (GPU @ 56C, CPU @ 66C)
* COOL TEST: GOOGLE EARTH TURNED OFF, USING 18" FAN PROPELLER TO COOL IT DOWN A.S.A.P.
* THROTTLING DISABLED (CPU AT 100% PERFORMANCE): TEMP4 HITS 45C.
45-55C are the limit temperatures for the TEMP4/TEMP5 sensors. If Dell could possible rise this in bios it would work the situation out. The question is: HOW FAR COULD IT BE DONE WITHOUT RUINING THE SPECIFICATIONS OF THE SYSTEM?!
The biggest stress on temp4/5 are caused by using GPU (Integrated or standalone), so they must definitely sensor temperature on the BUS
To override this you can get an app called RM Clock (Rightmark CPU clock utility) which is strong enough to override BIOS throttling and set it to force Throttling/CPU Clock to full power
Edit:
During my recent test, the recovery temp may be 46C not 45C as mentioned earlier... the 55C trigger worked this time as well.