Mac OS 10.5 64-bit Impresses
“...The performance difference between the 2.8GHz and 3.2GHz Mac Pro isn’t as great as the difference between running 32-bit code and 64-bit code. In fact, the 2.8GHz Mac Pro running 64-bit code is faster than the 3.2GHz Mac Pro running 32-bit code!”
A nearly 15% deficit in clock speeds aside, the 2.8GHz running 64-bit actually manages leads of up to 10% in many tests. We're wondering if/when Microsoft might finally merge their 32- and 64-bit variants of Windows in the same manner.