I've hit the limit on my 550W now too. 6HD's and 3 Optical Drives in here, AMD64 4000 and the very powerhungry 6800Ultra. If I so much as plug in my TV Capture card, let alone the 2nd PCI Gfx card I wanted to use to support 3 monitors on this machine like I used to do before I got the Nvidia power monster, it just keels over, unstable as hell. 12 HD's across my network too, I also use specific drives for single purposes in the same manner, my largest being 300GB. I can see myself happily using 800-900W too, need another Raid in here soon
Merrin