Use the UsePriorityScheduler parameter to disable
the use of thread priority switching (Windows only)
The Windows thread scheduler has a mechanism
whereby active threads get a boost in their priority level. This
improves Firebird performance, but may in some cases degrade the
performance of other applications unreasonably.
If you have problems with overall system response
time when running Firebird on your system, turn off the thread
The default value for this parameter is 1 (True).
The below example turns priority switching of:
UsePriorityScheduler = 0
Windows threading settings: PROCESS
PRIORITY LEVEL, PRIORITY
SWITCH DELAY, PRIORITY