> why firebird superserver can not run fast with multicpu

Due to its architecture, it can't distribute different threads to
different CPUs. Firebird will happily run on a multicpu box if you set
the CPUAffinity. Although Firebird itself will only use one of the
CPUs, other applications and Windows can use the other CPU so there is
some benefit.

> why we have to use classic server,

Classic works differently. Each connection spawns a new process, and
windows happily deligates that process to a particular CPU and doesn't
attempt to see saw it between processors.

> if there are a lot of database connection, we can not use classic server

You may need to edit the Firebird.conf file and choose more
appropriate numbers for classic.

>
> will firebird2 solve this problem
>

No, you have to wait for Vulcan.

Adam