Agreed, given one is 32 bit memory addressing and the other 64 bit. You would expect the 64 bit to be upto twice as long and adding optimisations in the middle

Agreed, given one is 32 bit memory addressing and the other 64 bit. You would expect the 64 bit to be upto twice as long and adding optimisations in the middle, but not equal. After all a 32 bit memory address is twice as much as a 64 bit one to handle behind the scene. Also he only used one compiler and would test with another compiler to confirm the results. Just to eliminate a possible compiler quirk in a quick way compared to checking the machine code.