Subject AW: AW: [firebird-support] Question about firebird 2.5
Author Olaf Kluge
Thank you!

> I have found the option "Superclassic" - after changing the option to
> classic-server!
> Here are the results of my testing:
> Firebird-Version seconds Query A seconds Query B
> 2.1 classic-Server 15 7
> 2.5 superserver 12 7
> 2.5 superclassic 12 7
> Certainly, I have on my local machine only 2 cores! All results was taken
> my local machine.
> I'm still interested, which option is the best in your opinion. And what
> about the switch? instsvc install -multithreaded
> There are another options in firebird.conf to change? (default cache page
> 75)

Talking about Firebird 2.5:

SuperServer was improved so that it can use more CPUs/cores if several
databases are on the server and accessed, but it never can utilize a SMP
environment if there is only one database involved. To enable SMP
support for SuperServer in case of several databases, make sure that you
"unbind" the server process from one cpu/core via CpuAffinityMask in

In general, Classic and SuperClassic are MUCH better options for SMP
environments. Both follow the same privcate/local cache model per
connection, thus you should use rather small page buffer values. If you
are using a 32-bit OS, then go with Classic. If you are using a 64-bit
OS, then SuperClassic might be an option as well. SuperClassic should be
a bit faster than Classic (TPC based test) and I find SuperClassic
somehow easier to manage. E.g. safe shutdown is possible, only one
process etc. Classic is more robust in case of a trashed connection. In
Classic, other connections won't crash in case something goes wrong with
a connection.

Check out my architecture comparison sheet:

and/or a demonstration video on SMP utilization in Firebird 2.5:

With regards,

Thomas Steinmaurer
Upscene Productions

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