IF YOU ARE WORRIED ABOUT GAMING AND YOUR COMPUTER READ THIS.
Just a fair warning to all of you thinking of buying an 8400, don't. Don't fall for it's price, it's model number, or it's memory. It sucks badly, and is probably equivalent to a 7900, except the 7900 doesn't lockup your PC if things get to hectic in a video game. Don't pay 50 bucks for a pain in the ass. And if you think it's only MY card it isn't, there are lots of complaints and threads about how much it sucks.
P.S: I had it for about two days, then I switched to a 8600 GT 512MB because I couldn't take having to restart my computer every 20 minutes of game play.