> The server is already running the "fastest"
> single core CPU money can buy, as going multicore is not an option.
> The application craps out in the presence of more cores. Redoing the
> application to run on a multicore system is too expensive, so that's
> not an option. The performance issues are database related, as the
> application itself doesn't use a lot of resources.

Perhaps I misunderstood something, but surely stopping your
application from 'crapping out' in the presence of multiple cores is
as simple as setting the CPU Affinity Mask when your application starts?

Look in your Help -> Windows SDK
Search for SetProcessAffinityMask

or use Google for examples.

You can then let the DBMSes use the other cores (For Firebird, this
will probably mean classic server or if you want to keep superserver
setting the affinity to a different number to your application).

Of course you may still want to investigate using a multi-core Linux
db server.

Adam