Subject Re: [firebird-support] Firebird performance on Dual Core machine
Author Adam
Hi Nigel,

> So, if you HAVE to run SuperServer on a multi-CPU (dual-core OR
> hyperthreading), lock it to one CPU.

IIRC, HT is a separate issue, most new machines ship with HT enabled
and we haven't had any problems for ages.

> If you want real performance from your multi-cpu box, use classic, which
> will scale, and use all available processors.

If only it were that simple. I suppose it depends on how you define
scale. About the only resource that is more efficiently managed on
classic than superserver is CPU. SS has a shared cache that can see
the scalability pendulum swing away from CS. Some of the index
enhancements in FB2 will make garbage collection less CPU intensive.
Whether this will be a noticable improvement in SS I do not know.

The agreed rule at the moment though is Multi-CPU requires either CS
or a CPUAffinity with SS. Which is faster really depends on how it is
used, what else is running on the server, and how many resources are
available. If it is highly CPU bound, then you will find classic much
faster, otherwise, you may be surprised. Fortunately, they are
interchangable, so you can test which one will work best for you.