hmmm? Are we talking about something different? Gurusan just said it was a single gtx 580.
The game play that we've seen at pressers may well of been on a 580. This guy is a graphics coder at DICE, and during his work he was saying he uses about 12 PC's to himself () but mainly the dual 580 setup. Because he was moaning how they have been waiting for ATI and nVidia to provide something they want in there drivers yet they still havn't, or something like that. It's all extremely complicated, he talks about stuff i can't even dream to understand
Testing is different to gameplay demonstrations though. He'll probably be trying to push the game engine to the limit, so needs the highest spec machine possible. When you implement new graphics features for the first time you can guarantee they are in there least optimised form, hence the need for a beast system.