You'll run it fine. Performance will be much, much smoother than in FSX. I run at 1920x1200 with most settings up high (texture res is my main feature, the others I'm not too bothered about) and your GPU is faster than mine (4870) and your i5 is clocked up at the same as my i7 is. You have less ram than me, but it prob wont be an issue. Just make the effort to stick with it, It took me a little while to go from missing the things FSX has that x-plane doesn't to where I am now - missing what x-plane has that FSX doesn't and not caring about the rest.