jamerica

Well, to be fair you may have 4GB installed, but you're not running Vista with 4 GB enabled when you play ArmA. I can confirm that XP-64 runs flawlessly with 4 GB installed/enabled with all the newest drivers (8800 GTS 640 MB & X-FI) and using the maxmem hack. I've seen no difference between XP-32 or XP-64. In Vista64, I have noticed slightly higher frame-rate than XP-64 with identical settings, although I have some extremely annoying micro-stutters every 1-2 seconds. Perhaps after SP1 Vista64 will be better, but I'm personally sticking to XP-64 for now. *NOTE* brand new nvidia beta drivers released today for Vista...169.01 has fixed all my micro-stutter problems, so I have no problem recommending it now.

XP-64: runs great, absolutely no problems. Vista-64: runs, but I get a slight graphics stutter every couple of seconds and it drives me nuts. You can also forget about running ArmA with 4 GB on vista, it just don't work.