"lurker" <[email protected]> wrote in message news:[email protected]... > Jonathan M Davis Wrote: > >> Now, assuming that all of that is taken care, if you're using a 32-bit >> binary on >> a 64-bit system, you're still going to be restricted on how much that >> program >> can use. It doesn't use the native word size of the machine to do what it >> does, >> and in many cases, running a 32-bit program on a 64-bit machine is slower >> than >> running a 64-bit version of that program on that machine (though that's >> going to >> vary from program to program, since there are obviously quite a few >> factors >> which affect efficiency). > > The efficiency claim is true. 64-bit architures have much more registers. > This can effectively double the code's performance in most cases. Loads > and stores can also use full 64 bits of bandwidth instead of 32. Thus > again twice as much speed. In general if you worry about larger binary > size, use UPX. Other than that, 64 bit code outperforms the 32 bit. We > want to keep the fastest compiler title, right?
OTOH, 32-bit code on 64-bit already vastly outperforms 32-bit code on a 32-bit machine anyway.
