Dell Latitude E6400 Thermal Throttling

Hi guys,

Specs as follows: 2.8GHz T9600 Duo, 8GB DDR2-800, Quadro NVS 160M, 160GB 7200RPM, A29 BIOS

Basically the issue is that after 10 or 15 useage the CPU bus and multi drastically throttles down as low as 400MHz - temps only need to be in the 60s to do this so it completely needless. GPU temp is 75-85C which seems quite hot with fan on 100% but showing as 0RPM (is it passive?)

There was a documented issue with this back in 2009 which seemed to be related to the integrated Intel Graphics chip and was supposedly fixed with a BIOS update.

However, for mine it worked perfectly for over a year - happily folding away 16+ hours a day on some occasions with no throttling, but over the last month or so it has been getting steadily worse. My first though was dust, so I took the back off and blasted out a few grains but it was pretty clean overall so I don't think that's the issue. I have tried manually setting fan speed to 100% constantly but only buys me a few minutes or so.

There is a lot of material out there with people complaining but none that I can find that solves it (BIOS was fixed circa A19 so I don't think it's that). I was hoping some of you guys may have come across a fix for this or could offer me some pointers.

Thanks in advance!

The GPU shares the heat sink and fan with the CPU and north bridge on the Latitude E6400. Have you taken the heat sink apart out and checked for dust accumulation? Especially the side of the heat sink which immediately faces the fan, you can’t see this area just by taking the bottom cover off, you can only get to it by either removing the heat sink assembly or fan. The dust which gathers here is resistant to compressed air blasts!