I installed the PSU and video card with zero difficulties. If I had more money I would have opted for a modular PSU design but I was able to easily wire-tie up and stow away the unused connectors/cables. Also, the GPU gets pretty hot (~75C) using default driver's fan control so I installed MSI Afterburner and all is well. GPU never gets above 60 C now. So anyone worried like I was that an upgrade like this won't work in an XPS9000, fear no more.
Sorry for bumping a old thread. Could anyone explain the steps to install a PSU in XPS 420?
1. The user manual (http://support.dell.com/support/edocs/systems/xps420/en/OM/HTML/parts.htm#wp1472790) appears to be less detailed than necessary. I believe that I have to remove the Processor Airflow Shroud Assembly, before I can remove the PSU. Is anything else that I should remove as well?
2. Does the metal release tab at the bottom of the power supply unit prevent the installation of longer PSU?
3. The user manual does not mention the P4 cable of the PSU. How many pin does it have, and what is it connected to?
Thank you for your advice.