> They can natively run 32 bit stuff with NO speed penalities No speed penalty compared to what?
Amd64 chips do run 32-bit code "natively", and are competitive as 32-bit CPUs in their own right. However you usually get a speed increase from recompiling as a 64-bit app. In 64-bit mode you have more registers and 64-bit arithmetic, which allow the compiler can generate more efficient code. From what I've seen 64-bit apps tend to be ~10% faster then the 32-bit equivalent. Paul
