RE: Weird Fan Behavior E6540 (A02 Bios)
Yep, I still have this problem. I'm pretty sure it has something to do with the thermal tables within the BIOS that dictate fan speed control. It is just way to liberal when it comes to turning the fan on and off. It seems that the range at which the fan turns on is very narrow.... Meaning when the CPU temp his some temperature, the fan turns on... However, if the temperature then quickly goes down, the fan turns off. Which would explain why the fan revs up and down and up and down randomly.
I have my own list of complaints with this notebook. First, the thermal system SUCKS... Dell are you reading this? This machine throttles down the CPU like crazy. Dell really is falsely advertising the performance of this notebook. Unless you purchase a cooling pad or operate the notebook in a walk-in fridge, you can't operate the notebook at 100% CPU @ 2.7 GHZ for a sustained period of time. The thermal footprint just won't allow it.
Another issue is the HORRIBLE screen. This TN panel might be the worst quality LCD screen I have ever seen in a notebook.
The inclusion of "high-end" AMD GPU is also a joke. If you are running GPU and CPU intensive tasks (i.e. gaming), the GPU and CPU both throttle down because it just can't move enough air to allow both to function as advertised.