hi etienne thanks for the info from what i read most webpages 64bit should be better than 32bit in general not just fsx but i believe its like going from C2D to quads in other words we might have to wait for our software(fsx)to be optimized for 64bit and this is a wild guess maybe the same way u can buy vista 32 or 64bit microsoft might have to do fs11 32bit n 64bit so we can unleash the great power behind 64bit os's??? ok all input from avsim simmers very happy to hear about them(but not limited to ofcourse lol).Dave

hey there well if it would have been the case where u went from 4gb on 32bit to 4gb on 64bit and u notice an increase it would be safe to assume its the thing to do(without changing hardware or software other than the os.) but it sounds like i might be due to the increase of ram which i believe u clarify also right!!thank you and at least someone its getting smoth flights hahah its all bumpy when I m behing the yoke(I like bush flying and the short runways hahaha lol)Dave

The difference is that: 1) A 32bit program on a 32bit op system can only use 2Gs of ram. 2) A 32bit program on a 64bit op system can use 4Gs of ram. 3) A 64bit program on a 64bit op system can only 8Ts (yes 8 terabits!) of ram. I was able to max out FS ram usage on my 64bit at 4Gs on my system, but it wasn't easy. The FS11 Program really needs a 64bit option. We've almost maxed out this 32bit system. I'm always "up there" with the PMDG airplane we're testing. A 64bit op system will really be a "Must" with that airplane.