Subject Re: [firebird-support] CPU Affinity
Author Mark Rotteveel
Post date 2016-01-19T21:14:14Z
Setting the cpu affinity to target more than one cpu will usually be worse for performance, as SuperServer is essentially single threaded and allowing it to run on multiple cores will cause expensive rescheduling.

SuperServer may perform better than Classic because CS has a smaller page buffer by default, and the synchronisation between processes is more expensive than in-process. The scale however will usually tip in favor of classic when using a large number of connections, as SuperServer will eventually be limited by how much it can do in its single thread.

Mark


----- Reply message -----
Van: "Hugo Eyng hugoeyng@... [firebird-support]" <firebird-support@yahoogroups.com>
Aan: <firebird-support@yahoogroups.com>
Onderwerp: [firebird-support] CPU Affinity
Datum: di, jan. 19, 2016 21:01

Hi Thomas.

Thanks for your answer.

I use SuperServer.

Why? Performance. It seems to run faster.

Hugo


Em 19/01/2016 12:21, 'Thomas Steinmaurer' ts@... [firebird-support] escreveu:
 

Hi!

> Dear Friends.
>
> FirebirdSQL : 2.5.5 64bits
> Operating System: Windows 2008 R2 Enterprise 64bits
> Server : Dell Poweredge R620
> 32GB
> 2 processors E5-2609 2.40 GHz
> 8 Cores
>
> To define CPU Affinity in firebird.conf I set CPUAffinity to 255, in a
> way to use all the 8 cores.

Which Firebird server architecture are you using? CPU affinity is only for SuperServer and the question is why do you bother with SuperServer on a multi-core machine when there is Classic or SuperClassic available?

--
With regards,
Thomas Steinmaurer
http://www.upscene.com

Professional Tools and Services for Firebird
FB TraceManager, IB LogManager, Database Health Check, Tuning etc.

> Does it make sense or could be better to use less cores, like core
> 5,6,7,8 or 3,4,5,6?
>
> --
>
>
> Atenciosamente,
>
> Hugo Eyng
>
>
>
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-- 


Atenciosamente,

Hugo Eyng