I would definitely focus more on processor speed than on RAM. I've only got 512MB of RAM and mine runs fine and doesn't lock up since the release of SR1. I prefer AMD (husband recommends AMD and he builds computers used by Northrop Grumman Ship Systems and the United States Navy). I don't like Nvidia cards because you constantly have to upgrade your drivers (about once every few weeks) and I've had trouble getting them to work with other software that I use. I use the ATI Radeon cards and have had wonderful success with them.