Engadget noticed Dell has a power adapter upgrade program for its Studio XPS 1645 notebook. This should resolve the throttling issues that many users experienced. This program was apparently rolled out in February, but it hasn't received much press attention yet.
We're just now hearing that the company apparently launched a program back in February to replace the stock 90 watt power adapters with more capable 130 watt models for anyone suffering this affliction. However, this doesn't seem to be a proper recall, as the reports we're seeing indicate only customers who call and complain have been made aware of this program. So, consider yourself made aware.
Here's a snip from Dell's site that describes the problem:
Announced in February 2010: Through its various community forums, Dell announced the identification of throttling issues on the Studio XPS 1645. These throttling issues can result in power and performance impact which varies by degree, depending on configuration and usage. This throttling of the processor, and sometimes the graphics card, hinders overall system performance while running highly intensive software applications, to include certain games or High Definition video applications. Under these conditions, the system can approach the maximum power available from the 90-watt adapters that shipped with the system which can result in the throttling.
Throttling issues occur for various reasons. This Studio XPS 1645 throttling issue is a limitation related to the 90-watt adapter. The resolution is to update the system BIOS, and for some, replacing the 90-watt adapter with a 130-watt adapter. Enclosed, please find additional information regarding the XPS 1645 power supply and resolution instructions.