Speed of Flight is right. Maxing out FSX is a no brainer. There is more than enough information on this forum to confirm this statement. Do the research.

Thank you! Sheesh!
It is possible. Very possible, in fact. I haven't adjusted my settings for over a year, now. CFG is edited for max texture size 4096 for Rex2, ALL traffic 100%, all scenery 100%, true that the 2d panel transparency is off, but who wants or needs to see through a panel? Water, all settings that go up to make FSX work harder and look better are 100%. P-factor, gyro-drift, everything. ALL settings.
How I did it, you ask? Easy. Whenever a new and expensive PC part comes out, buy it. Heavy duty PSU, Big Video card, highest-end CPU (either manufacturer will suffice for maxxing sliders), fast, low-latency DDR3 ram, and a very tune-able MB for O/C'ing the garbage out of that new, high-dollar CPU. Secrets revealed. It takes money, really. Can't compromise on the expense or the quality of good parts if you expect FSX to not compromise on your experience.
All the facts aside, time for some opinion. [glow=yellow,2,300]To the original poster:[/glow]
I use AMD processors because they're cheaper, but if you want great performance, I do recommend using intel stuff. All the Benchmarking programs are designed to fit them best, and if you start this project, the next thing you do will be trying to speed it up. Go with the i7-930. 920 rox, but you get a little more zoom out of the 930.
Get yourself the 5870 or 5970 ATi cards, only because they freakin ROCK. No better out there. If you want to use that card and a great CPU, you need power to spare during a heavy workload. I use an 850W Antec, but things are getting somewhat power hungry. Go with AT LEAST that much, or better. Ram is everywhere, choose the lowest latency DDR3, and you'll be fine. I really dig the ROG crosshair3 MB and the Intel equivalent Rampage2 or whatever that one is. Look for "Republic Of Gamers" stuff for that.
Most importantly, do your homework. Numbers matter with all this stuff, but if you get the best there is out there now, you should be fine. This year's hardware releases have really put FSX users ahead of the curve. Flying it has been a pure joy since I stepped up my hardware. It will be for you, as well.
Good luck, and look for the deals! But get shoppin, so we can all see someone NEW ROCK FSX, and put all the doubters in a tailspin!
See you up there.