Call SetPageBuffers to set the number of database page buffers. 

When a program establishes a connection to a database, InterBase allocates system memory to use as a private buffer. The buffers are used to store accessed database pages to speed performance. The number of buffers assigned determines how many simultaneous database pages it can have access to in the memory pool. Buffers remain assigned until a program finishes with a database. 

For more information on page buffers, refer to 'Setting database cache buffers' in the InterBase 6 Programmer's Guide.