Re: 32 bit or 64 bit in this situation?

Unfortunately, my chipset supports a max of 4GB and that is what I
have installed. This means that both 32 and 64 bit OSs have the same
amount of memory available, viz 3.12 GB. See MSKB 929605 for more

Are there any performance benefits in this situation to using 64 bits
over 32 bits (Windows and/or Linux)? I am only interested in better
performance and nothing else like driver availability.

Since you're only seeing 3.12 GB with a 32 bit OS you would get almost a full gig more with 64 bit. That would improve performance if you sufficiently load the system - you would be able to run more applications before the system would have to start using the page file. An important issue is whether or not the BIOS supports memory mapping above the 4 GB address space. In order for the OS to use all 4 GB for itself and applications the memory addresses for hardware need to be moved up.