>While in general there may not be that much of a % difference between
the 2 chips,
>there's a huge gap in Postgres. For whatever reason, Postgres likes
Opterons.
>Way more than Intel P4-architecture chips.
It isn't only Postgres. I work on a number of other server applications
that also run much faster on Opterons than the published benchmark
figures would suggest they should. They're all compiled with gcc4,
so possibly there's a compiler issue. I don't run Windows on any
of our Opteron boxes so I can't easily compare using the MS compiler.