BF2S Forums What's the deal with 64bit?

While 64-bit architectures indisputably make working with huge data sets in applications such as digital video, scientific computing, and large databases easier, there has been considerable debate as to whether they or their 32-bit compatibility modes will be faster than comparably-priced 32-bit systems for other tasks.
Theoretically, some programs could well be slower in 64-bit mode. Under some architectures, instructions for 64-bit computing take up more storage space than the earlier 32-bit ones, so it is possible that some 32-bit programs will fit into the CPU's high-speed cache while equivalent 64-bit programs will not. In basic terms moving 64 bits at a time to perform otherwise 32 bit work simply requires more processing effort to/from memory. A common argument is that, in applications like scientific computing, the data being processed often fits naturally in 64-bit chunks corresponding to double-precision floating-point types, and will be faster on a 64-bit architecture because the CPU will be designed to process such information directly rather than requiring the program to perform multiple steps — this is erroneous, however, because most 32-bit CPUs already have a 64-bit wide data bus and 64-bit registers for floating-point quantities. The only speed advantages come for manipulating 64-bit integer quantities, but this is rarely a performance-limiting task even for applications (such as large-file I/O) that require such manipulations.

The main disadvantage of 64-bit architectures is that relative to 32-bit architectures the same data occupies slightly more space in memory (due to swollen pointers and possibly other types and alignment padding). This increases the memory requirements of a given process and can have implications for efficient processor cache utilization. Maintaining a partial 32-bit model is one way to handle this and is in general reasonably effective. In fact, the highly performance-oriented z/OS operating system takes this approach currently, requiring program code to reside in any number of 31-bit address spaces while data objects can (optionally) reside in 64-bit regions.

I'm running a Windows XP 64. I must say that while certain applications like Photoshop and video editing software run a bit faster, there is a minor drop in gaming framerate. Not only that, but WOW64 is incapable of running some older applications, like Doom. I don't know how Vista is going to handle 64 bit, but if you are still using XP exclusively and want the 64 bit version, either have both versions on dual boot, or keep a spare computer handy.