Dell Dimension XPS 720 is way to loud. How to qiute?

Hello,

I have a Dell Dimension XPS 720. It's running dual GeFore 8800 Ultra video cards. When I enable SLI games suddenly become VERY jerky but this is not my main concern. My main issue atm is how LOUD it is. This was not always an issue and only started occuring about a month ago. The system is 4 months old. When starting wow, a very non-graphical intensive game, the fans start ramping up so the point that it sounds like a jet plane. SLI or not has no effect on this. I have the side of the case open with a fan blowing across it as well but this dosen't help at all (just makes it nosier).

It's fairly clean in my apartment as I run air filters and I am a bit of a clean freak and I've also checked for dust/ect that might be interferring with air flow and it's very dust free insdie the case.

I was hoping that someone might of run into this issue and found a solution. I was looking at going to a liquid cooled setup and/or replacing the fans with quiter ones or using sound dampening pads. Any suggestions would be most welcome either software or hardware related.

*I've run numerous updates for the chipset (680i SLI SPP), the vidoe cards, the OS (Windows Vista), ect.
*The ambient temperatue is rather cool (I keep the windows open) roughly 65 degrees +/- 10 degrees I'd say is fairly accurate.
*Temp monitoring shows the following:
core1 91 degress (C)
core2 89 degress (C)
core3 81 degress (C)
core4 81 degress (C)

GeForce 8800 Ultra #1
GPU 80 degress (C)
Fan 64%

Gefore 8800 Ultra #2
GPU 80 degress (C)
FAN 60%