Subject Re[4]: [firebird-support] Firebird performance on Dual Core machine
Author Andi Wangsadijaya
Hello Helen,

On Wednesday, January 4, 2006, 6:32:17, You wrote:

>>You told that the performance of firebird superserver version will be
>>drop on SMP Machine (including dual core and hyperthreading).

> YES - *if* you allow the Firebird server's CPU affinity to switch between
> multiple CPUs. But NO if you keep (or re-set) the Firebird server's CPU
> affinity to ONE SINGLE CPU.

>>At the other side, you told that performance will die if I change the affinity
>>mask to two CPUs.

> Yes, that is correct. I think you have missed the point that the
> CPUAffinityMask setting is a bitmask, i.e. the number 1 DOES NOT mean "one
> CPU" and the number 2 DOES NOT mean "two CPUs".

I just tried the simple tests firebird super server between using
CPUAffinityMask at value 2 (use the 2nd CPU) and at value 3 (use both
CPUS) on AMD Athlon64 X2 3800+.

I thought at the CPUAffinityMask = 3 the performance would be drop, but it
didn't happened. The both results is same. Is it just a abnormal
case? If it's true, why the three test has the same results?

Best regards,
Andi Wangsadijaya

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