I run dual-monitors at 1440p on 32GB of RAM and I think the most I ever see utilized is about 14-16GB. And that's with two browsers, email, a flash game, RDP, and a system tray so wide I could use it to bridge the Bosporus. At 1080p on each of my 5 clients and a dxNothing sidebar, they're sitting at about 1.5GB each in Shrine of Two Moons. After a long play session, they'll climb to 2GB each or so, but that's about it.