Originally Posted by omg_dastard!
(p.s would going SLI, or upgrading motherboard and getting a 45nm Quad make a huge difference?)
I would try it on your current system and see what you think. The main reason to get a Quad IMO is to reduce the dreaded "blurries", which FSX is known for. FSX gives the lowest priority to ground texture loading, so if you are flying fast the ground textures can't load in fast enough causing blurred ground textures.
With my style of flying low and fast I was always flying over blurred ground textures with my 3.6GHz Dual core, but now that I've switched to a Quad I am much happier, even though it is 600MHz slower. At least I can fly over sharp textures now.
Many people don't have issues with the blurries becuase they take off and go up to altitude, where blurries are not so much an issue, but if you plan on doing a lot of low altitude flight a Quad is ideal.
As to SLI, I can say with just one 8800 GTX you can run FSX at 1600x1200 with 16xS Supersampling forced via enhancer with no problems. If you kow whay kind of performance hit 16xS causes then this will tell you how much GPU headroom FSX has, so much so that your CPU is where your performance always hinges. People have said FSX does not support SLI, but the developers have always said SLI works at the driver level and not the application so there is no reason it should not work.