I'm running an i7 920, 12GGB 1600 RAM, 4850, 30GB OCZ SSD (dedicated for wow). I currently have Firefox (18 tabs open), ISboxer, and 5x wow open and am sitting at 5.31GB of used memory. If I add photoshop, dreamweaver, multiple explorer windows and a few other apps, i run around 8.5GB. I started with 6 and was getting good performance, but added another 6 so I could run more in addition to wow.