Default FCGId PHP sub-processes
When PHP scripts are run via FCGId, each domain will have the number of PHP processes
set in this field running at all times to serve requests. You
can increase this from the default of 4 to improve PHP script latency, or
decrease it to reduce memory use.
Setting it to None will cause PHP processes to be launched only
as needed on demand, and to be cleaned up after some period of inactivity.