Showing posts from August, 2007

The AMD Athlon™ 64 Processor Operational Modes (also applies to Intel chips with EM64T)

Legacy Mode: Legacy mode is what the processor defaults to in basic 32-bit software. If you run a 32-bit Linux or Windows installation you’ve been running in legacy mode; if you’ve looked at any performance benchmarks it should be obvious that not only is the AMD Athlon™ 64 processor more than happy to run this way, it delivers excellent performance while doing so. Compatibility Mode: Compatibility mode is designed for a 64-bit processor that still needs the capability to run 32-bit applications. The AMD Athlon 64 processor is capable of this natively, which eliminates the need for 32-bit emulation on the hardware level. Long Mode: True 64-bit Long Mode is intended for a native 64-bit OS environment where the application is also running 64-bit. Windows XP Professional x64 Edition is capable of using both modes, and the AMD Athlon 64 processor is capable of switching between 64-bit Long Mode and Compatibility mode from within the 64-bit OS. Why Move to 64-bit? If 32-bit systems offer e…