My computer is a Dell, Intel Quad-core, w/ Q800 @ 2.33 GHz, 8.00 Gb RAM, and an ATI Radeon HD 3400 series graphics card. It's about 5 years old, but it runs like a charm, I tried out both World of Warcraft and Rift and they ran fine, no lag at all. I tried using a few 3rd party viewers as well, that didn't help either. I'm super-excited to get involved in Second Life, so as you can imagine, this is driving me up the wall.