Help with new power supply
I have an HP Pavilion p6310y I would like to stick in an ATI 5570 graphics card. Problem is the system only came with a 300 watt PSU, ATI's site recommends 400 watt. Do I need to be careful which PSU I buy? Can anyone recommend an affordable 400+ watt unit please that will not harm my machine?
p.s. I heard a rumor that I can get away with my 300 watt unit and the 5570, should I try this, or will I risk harming my machine? Thanks!