Lars Schouw wrote:
Victor
Thank you for the nice and useful answer. |-)
tomshardware tests ....hardware I want to see how a monte carlo
simulation (software) runs on the same CPU but with a differerent OS
and compiler setting - build for 64 bit
I think Victor is saying you're better off trying a newsgroup that is
more related to your question. comp.arch, or some MS group on 64 bit
stuff would probably get a useful response. He is right.
As an aside, my experience is that there is a significant speed-up but
this is not because of the inherant "64 bitness" but because going from
32 bit X86 ISA to AMD64 means the compiler has some more registers to
play with and does allows the compiler to do a much better job with code
generation. There is a hit when you start storing 64 bit pointers as
they use twice the memory. My experience with mips 32 bit (o32 and n32)
vs the 64 bit (n64) instructions was that n32 was significantly faster
than n64 on some applications (usually memory bound apps).
In the case of AMD64 vs X86-32, I don't think I've ever seen a
performance regression going to 64 bit.
Every performance question ends up with this answer - "Test it". Only
you are qualified to do that.