Recent numbers from Microsoft suggest almost half of all Windows 7 users run the 64-bit version. When it comes to gamers, though, the x64 flavor looks to be even more popular. So shows Valve's Steam Hardware Survey for July 2010, which pegs Windows 7 x64's usage share at 30.32%—higher than any other operating system in the list, including Windows XP x86:
Interestingly, the sixth most popular OS (after Vista x64) is Mac OS X 10.6.3. Adding the different versions together, OS X's usage share totals about 5%. Not too shabby, at least if you consider the Mac version of Steam has barely been around for three months.
Other noteworthy stats: AMD's Radeon HD 4800 series are now the most popular graphics cards among Steam users, but AMD's graphics usage share is only 33% (Nvidia's is 59.11%). 1680x1050 is the most popular resolution, almost a third of users have quad-core CPUs, and Intel still dominates with a sizable 72% CPU usage share.