O Plameras wrote:

> Given two CPUs one 32-bit and another 64-bit with the same Megahertz or
> clock speed, the 64-bit is significantly faster.

That is not right.

As you saw from the sizeof experiment, the only thing that changes
when going from 32 bits to 64 bits is sizeof(long) and sizeof (void*).

Given the same application compiled for the two architectures (and with 
everything else being equal), the 64 bit one will be slightly slower
because all pointers are 8 bytes in size as opposed to 4 bytes on 32
bit architectures. The larger pointer size on 64 bit systems means that
more memory to CPU bandwidth is chewed bu transferring the larger
pointers to the CPU.

Also remember than most high end 32 bit Pentium CPUs have had a 64
bit wide data bas for ages. This was done to maximize the bandwidth
from slow dram to the CPU caches.

Erik

PS : I'm on the list, You don't need to CC replies to me.
-- 
+-----------------------------------------------------------+
  Erik de Castro Lopo
+-----------------------------------------------------------+
"It has been discovered that C++ provides a remarkable facility
for concealing the trival details of a program -- such as where 
its bugs are." -- David Keppel
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