I have searched for this answer, but couldn't find it. Do I have to plug a power cable into both connections on the card? I'm running an Antec True 480. The specs on the PSU show 22amps on one 12 volt rail. I have only one power cable plugged in (the one directly across from the DVI connection I'm using). All goes well until I try to play any game, view a video clip or slideshow. When I do any of these, I hear the video card fan go into high gear, then the weird artifacts appear, and the monitor goes to sleep. Also at boot up I get very weird artifacts until the actual BIOS screen appears.