64-bit computing in theory and practice@ 2005/10/31
The truth is somewhat different from both of these visions. 64-bit computing won't bring us two times the performance in an amazing overnight transformation of the PC, as the move from 8 bits to 16 seemed to do back in the day. But it's not a pointless exercise in shuffling bits, either. The 64-bit extensions to the venerable x86 instruction set architecture (ISA), including AMD64 and Intel's code-compatible EM64T, actually offer some tangible benefits with few drawbacks. These extensions to the x86 ISA offer a much larger memory address space, bring a cleaner programming model with performance benefits, and retain backward compatibility with existing 32-bit applications.
In order to help you navigate through the hype, we nabbed a pair of 64-bit processors from AMD and Intel and tested them with the latest release candidate of the 64-bit version of Windows XP. Read on for our take on the move to 64 bits, including a look at the performance of the latest CPUs in Windows XP Pro x64 Edition with both 32 and 64-bit applications.