Farcry2 is 1 of the game benefit from x64 the most.

i have some benchmark from someone else:

XP Pro 32-bit
* Average Framerate: 35.38
* Max. Framerate: 50.80
* Min. Framerate: 28.32

Vista x64 (DX9)
* Average Framerate: 39.84
* Max. Framerate: 58.35
* Min. Framerate: 31.20

Vista x64 (DX10)
* Average Framerate: 41.11
* Max. Framerate: 65.32
* Min. Framerate: 33.99


sorry, i dont have Fallout.