Hello,
Is it possible to put a GeForce 580 GTX video card, which requires a 600 watt Power supply, into my XPS 420? I am currently using GeForce 8800 GTX.
Probably not. Some 580's have been charted at 450W total system power with at least 400W very likely. XPS 420 only has a 375 or 425W(Quad core most likely) PSU.