I pondered on this question for sometime now and have waited to see if games would ever see need of a 64-bit OS. However, they've been far and few. One game which is yet to be release called BC2 won't use it and here is the reason why: source This answer to the use of 64bit OS piqued my curiosity because I wondered if most developers have this sentiment towards 64-bit. That if they can optimize their games without the need for additional memory or additional virtual memory it would be a RD cost benefit for them to just use 32-bit. I'm looking at this from the practicability aspect of how a 64-bit environment would work with these games. Sure you can get a game to use 8 Gigs of ram but is it practical to do so? In other words is there any tangible need for more memory for that game? So far the answer is no. Other games to be released in a few weeks are Mass Effect 2 and Alien Vs. Predator. Neither of which state if 64-bit will be supported. ME2 system requirements state that they recommend 2 gigs of ram so I don't believe it's likely that more will benefit the game. So, what am I getting at? With all these PC titles being released there is still no indication that developers are in mass to adopt 64bit OS. As one already mentioned it simply no practical benefit for their game. In the end if you are gamer more so then anything else do you really need a 64-bit OS? More then likely no you don't. However, if there are other applications that demand it's use it maybe something you would need to research to see if it's a benefit to have.