I've got some numbers for a raw 8.1.5 database with 1G of cache on Solaris 2.7 showing that 32-bit Oracle can be as much as 3% faster than 64-bit. I would expect the result to favour 32-bit more strongly with smaller SGA sizes, but of course 64-bit would win at larger SGA sizes. The difference would be less for filesystem based databases. The bottom line is that there is not much difference, but that you are better to stick with 32-bit Oracle unless you need a large SGA.

I would like to know if you have made performance tests between 32 and 64 bit Oracle 8.1.7 for Sun Sparc.