I have a 9 month old Antec 300w power supply that came with my case that says it has 15A to the 12v rail. I currently have an Asus mobo, Barton 2800+, eVGA 6600GT, and an 80 gig HD in there. Runs perfect. I'm upgrading to an ASRock Dual SATA2, Opteron 146, ATI X800 GTO modded to 16 pipes. Do you guys think I need a new power supply, or will this one do the job? I'm only spending $430 for the three new parts and really don't feel like throwing another $50-$75 into this unless it's absolutely necessary. Thanks! EDIT: Just thought about something. My new card will be PCI-Express. I'll need a new power supply regardless, right?