Third one just died in my Dell PC which is 15 months old. First two were covered by warranty but Dells says, "Tough luck Charlie" on this one. Anyone have a good suggestion for a "NON-ATI" alternative? Remember, this XPS8100 has only a 400W power supply.
what model is your current psu?
can you replace the psu with something like antec earthwatts or corsair builder cx 430 v2?
nvidia doesn't have good entry level gfx cards. their well-performing cards start from gtx 560 (for the current 500 series cards).