How big PSU for HD 5770 card

[firecat318]

My current stock computer only has a 300W PSU so I am pretty sure I am going to have to upgrade it in order to put in an ATI Radeon HD 5700 card. Right now it has an integrated POS that is worthless. How big of a power supply should I get so I can use the 5770 card? Is 500W enough?

 

[Marshillboy]

Try to input your hardware into this PSU calculator, and round up to the next 50 or 100w to see how much power you really need.

http://extreme.outervision.com/psucalculatorlite.jsp

 

[foothead]

Make sure your PSU has that wattage on th 12v rail. Some cheat by including the other rails in their wattage number. It'll say what you need on the label, just take the +12v amperage, multiply by 12, and there you go.

Now, AMD recommends 450w for the 57xx cards. This is usually not necessary, it depends on your other hardware. The card itself uses about 80w.