Linked by Tony Bourke on Thu 22nd Jan 2004 21:29 UTC
Benchmarks When running tests, installing operating systems, and compiling software for my Ultra 5, I came to the stunning realization that hey, this system is 64-bit, and all of the operating systems I installed on this Ultra 5 (can) run in 64-bit mode.
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Comparing 32 and 64 bit benchmarks
by Michael Meissner on Sat 24th Jan 2004 13:00 UTC

Assuming you don't have additional instructions or registers in 64-bit mode and that you don't have in 32-bit mode or heavily use 64-bit integer data types, the main effect of running in 64-bit mode is that your cache is less effective. This is because the cache is fixed size, and you are now putting in larger variables (namely larger ints and pointers). You would see this effect more if you were just on the edge of thrashing the cache in 32-bit mode, 64-bit mode would completely thrash.