Re: People still make these older CPUs last I checked...
Short form - you just have to try it both ways and see.
Long form - 64 bit code has access to more registers and that gives the optimizer more chances to do something clever. Fewer memory transfers, which is a nice speedup, can lead to less cache poisoning, which is a really nice speedup. After the 64 bit transition in the early 2000s, it took a while for the compiler writers to catch up but now it's barely even a decision. 64 bit implementations of mmap() can speed up your I/O maybe 5%. On the other hand, yes, if memory is in really short supply then you want to avoid paging and swapping no matter what you have to do.
Biting the hand that feeds IT
