Originally posted by: yusux
x64 supports up to 128gb of ram, x86 only 3.25gb of ram, x86 has better performance on most games and better driver/software compatability, but I would still recommend x64
Sorry but no, thats not even a little bit right.
x86 supports 4GB of RAM; however, 2GB is reserved for kernel space applications/programs. Thus, you have 2GB available for user space programs and drivers (For instance, Graphics and Sound Drivers, starting with Vista, were moved to the User Space).
There are registry modifications that will allow you to decrease the Kernel Space allocation to 1GB; however, these are very bad ideas given that your Virtual Page Table is then messed around with.
With this in mind, without the FILE_LARGE registry modification, a single process is limited to 2GB of memory. With the modification, this increases to 3GB per process.
x86 and x64 have the same compatibility and, in general the same performance.
x64 will rarely be more than a few percentage points slower in general applications due to the Larger Pointer Size (4 bytes on x86 and 8 bytes on x86-64); however, in applications where the larger memory address space, and particularly computation intensive applications are used, x64 can offer a sizeable performance increase.
As for drivers, it is rare to find a manufacturer who has not provided 64bit drivers for their device today.
Video codecs are; however, a weak spot still given that a 32bit codec will not be recognized by a 64bit application (and vice versa).
-Kevin