Hi,

> Those Xeon thingies have multiple-core CPUs.

AFAIK a Xeon processor is a single-core CPU.
HT processors have an additional set of registers, an additional APIC,
and some other small modifications, but they do not have a second
core.

We are going to see dual-core CPUs in the near future, but up to know,
they are not available.

> They call it ``HyperThreading''
> or ``HT'', for short. Hyperthreading is very similar to real SMP,

HT, also called SMT (Simultaneous Multithreading), is quite different
from SMP. With HT enabled, the OS sees two processors, but there is
only one processor/core. To make use of HT (i.e. to gain a performance
benefit from it), the OS scheduler must be aware of HT.
The scheduler of Windows 2000, for example, is not aware of HT. It
detects two CPUs and thinks it works on a SMP system. Many people have
even reported a little performance drain with HT and Win2000, so it is
better to turn of HT on a Win2000 system.

XP and Win2003 Server support HT.

> so yes, you
> should do with your firebird configuration whatever you'd do on a SMP machine.

I am not sure about this. I remember some posters which reported
problems with Firebird and HT. I have read many answers which
proposed, as a rule of thumb, to turn off HT when you work with
Firebird. But I'll rather leave this one to the Firebird gurus.

However, I am currently working with a dual Xeon system with HT enabled and Firebird
runs fine on it. Maybe this is just luck.


Christian