There are new configuration files available for Firebird 3 and Firebird 2.5 (SuperServer, SuperClassic, and Classic), to better serve various scenarios: 1 big database, 1 big database and several small satellite databases, many databases (in case of SaaS, for example), with tuned memory parameters for RAM 8-12Gb and RAM16-32Gb.  Configuration files for discontinued versions (1.5, 2.0, 2.1) also have received small updates.

We hope that these improved configuration files will help to resolve many typical performance problems with Firebird.  
Download here.