TD I am not a computer geek or Dell sales rep... but I get excellent results from a fairly new Dell XPS 400 running X-Plane. X-Plane 8.40 is more demanding of computing power than MS FlightSim and I get framerates including predominantly clear skies (high processor demand) of about 59 frames per second. The main things you want are at least 1GB memory, a strong graphics card say 250MB, and the new dual-core processor. Once again I am not a computer geek but nothing speaks like success and I am getting it with this Dell. It was $750 about 6 months ago.