I've tried searching online for performance comparisons between MySQL
32 and 64-bit platforms, but can only find benchmarks dating back a
few years using MySQL 4.x . Now we're on MySQL 5.0 and I cannot seem
to find such evidence backing up the speed benefits (or otherwise) of
a 64-bit processor.

We've got the MySQL Enterprise 64-bit version running on an Intel Core
Duo based server system. However, a Chinese language fulltext search
patch being developed by MySQL in China is to be installed for us -
but only the 32-bit version of MySQL is currently available, which
effectively means downgrading if I want to benefit from that patch.

- but I cannot find evidence of whether 64-bit is even beneficial in
the first place.

Anyone able to give me some semi-concrete performance comparisons?

Thanks!

Terence