Subject Re: Hyperthreading and Hardware SMP
Author jbperez808
--- In, "Myles Wakeham" <myles@t...>

> What exactly do you anticipate to be problems with Hyperthreading that
> people may encounter, that don't turn this off? And what Windows
> systems would be affected by this?

In SMP machines, Superserver-based Firebird needs to be
tied down to a single processor by setting processor
affinity. Otherwise, like Helen mentions, it
will jump from one processor to another and cause
a significant performance drop. I'm guessing there's
no way to set affinity for HT-enabled systems so
you have to turn it off entirely.

What I'm concerned about is that people who are using HT
would not want to turn it off just to be able to run
a Firebird-embedded-based off-the shelf app especially
if they are relying on another app where HT really
speeds things up for them.