Re: 64-bit vs 32-bit performance ... backwards?

J. Andrew Rogers wrote:

> We have been using PostgreSQL on Opteron servers almost since the
> Opteron was first released, running both 32-bit and 64-bit versions of
> Linux. Both 32-bit and 64-bit versions have been bulletproof for us,
> with the usual stability I've become accustomed to with both PostgreSQL
> and Linux. We have been running nothing but 64-bit versions on
> mission-critical systems for the last year with zero problems.
>
> The short story is that for us 64-bit PostgreSQL on Opterons is
> typically something like 20% faster than 32-bit on the same, and *much*
> faster than P4 Xeon systems they nominally compete with.

Since you sound like you have done extensive testing:

Do you have any data regarding whether to enable hyperthreading or not?
I realize that this may be highly dependant on the OS, application and
number of CPUs, but I would be interested in hearing your
recommendations (or others').

/Nis