
Here are the ATI recommended power supply requirements for the new ATI Radeon HD 5770 and 5750 video cards that just became available:
450 Watt or greater power supply with one 75W 6-pin PCI Express® power connector recommended
600 Watt and two 75 watt 6-pin connectors for ATI CrossFireX™ technology in dual mode
http://www.newegg.com/Product/ProductList.aspx?Submit=ENE&N=2010380048%20106793261&name=Radeon%20HD%205000%20series
Technical reviews:
http://www.tomshardware.com/reviews/radeon-hd-5770,2446.html
http://www.anandtech.com/video/showdoc.aspx?i=3658
Power consumption, temperature, and noise levels are very encouraging. 😀