Embedded server opens database for exclusive access. If all the
threads are trying to open the same database and your code includes
repeated attempts to connect to the DB in case of any error, you will
get serialized access to your DB. Your numbers are very close to my
assumption - 7ms*200threads = 1400ms average access time.

Best regards,
Pavel Kutakov
SQLLY Development
Interbase/Firebird Development Studio - complete development solution.
http://www.sqlly.com