Hi Geoff,

> Helen Borrie helebor@... [firebird-support] wrote:
>> At 02:36 p.m. 30/10/2014, Geoff Worboys
>> geoff@... [firebird-support] wrote:
>
>>>Doesn't that depend on how they implemented the separate threads?
>>>SS does/can use different threads for separate connections to the
>>>same database, can't it? So if the threads operate over separate
>>>connections then wouldn't SS be able to use multiple CPUs?
>> Not in 2.5 (Dmitry will correct me if I'm wrong, I hope!),
>> but I'm fairly sure it's a Yes in Fb 3. AFAIR, in 2.5,
>> multiple CPUs will be used for connections to multiple
>> databases if they are available. We're talking here about SS.
>> SC behaves the way you describe, as far as I understand.
>
> Hmm... Yes, my mistake, you are correct (as if there was ever
> any doubt :-)
> http://www.firebirdsql.org/file/fb25_architecture_comparison.pdf

I once did a short video with a very simple/naive SMP capability test across SS and SC.
http://www.iblogmanager.com/download/demos/firebird/fb25_architectures_smp.html

Although with SS internally requests to the same database from different connections are serialized (at least that is what Dmitry confirmed to me in the past), SS isn't strictly bound to a single core for a single database. There are other threads which may occupy other cores a bit but to a much lesser degree as in SC/CS for a single database.



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

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