Subject Re: [firebird-support] FB 1.5.1 and Multi-processors
Author Paul Vinkenoog
Hi Daniel,

> Unfortunately, I'm not in a position to comment any further, since
> I don't have a SMP computer to test it. Just by curiosity, did you?
> (Don't worry, I'm not doubting you, without any formal proof it's
> hard to definitely give an answer either way, yours or mine) And on
> the other hand, you have some saying that it works fine on Linux
> SMP, but are not giving more details than that.

No, I don't have an SMP box. My answer to the original poster was
based on postings from developers (and users) in firebird-devel.
Which, in a nutshell, boil down to:
- No SMP support in Superserver so far.
- SS Linux performance doesn't degrade on an SMP machine but it also
doesn't improve (that is, Linux SS doesn't benefit from the presence
of more CPUs).
- With SS Windows you do get a performance hit due to the see-saw
effect, but you can remedy this with the CpuAffinityMask parameter.

Iow, if you want to really reap the benefits of SMP (as opposed to
merely not losing performance compared to a uniprocesssor machine)
you have to go Classic, both on Windows and Linux.

Paul Vinkenoog