HPUX11.23 is a 64-bit OS. This means that the kernel itself is 64-bit, and needs a 64-bit processor to run on. It will of course run binaries that are just 32-bit.
Why offer 32-bit and 64-bit binaries for an app rather than just 64-bit binaries?
Performance.
64-bit gives you bigger address spaces, bigger registers etc. etc. In certain workloads thats gonna make things much quicker... for other workloads, simply allocating and using all these big data sets just slows things down - you don't need em, so why allocate em? Also memory utilisation - 64-bit processes tend to eat up a lot more memory. Hence 32-bit executables...
My advice would be to download both and try a load test with both - you might just find the 32-bit executables are faster...
HTH
Duncan
I am an HPE Employee