Currently running FSX on a 2 year old XP Pro system and feel it

You should have posted this in the hardware forum. I am sure the mods will move it asap.Anyway, if it were me, I would get a Quad-core setup, especially if I were planning to keep the computer more than a year or two.I can only tell you what I personally would do, and that is quad, 4 gigs of ram, and Vista 64. The HD3870 cards look VERY nice and promising. There is a thread about the dual-gpu 3870 card in the hardware forum that you might want to look at.RhettAMD 3700+ (@2585 mhz), eVGA 7800GT 256 (Guru3D 93.71), ASUS A8N-E, PC Power 510 SLI, 2gb Corsair XMS 3-3-3-8 (1T), WD 150 gig 10000rpm Raptor, WD 250gig 7200rpm SATA2, Seagate 120gb 5400 rpm external HD, CoolerMaster Praetorian