Subject FB_INET_SERVER.EXE using all the memory


I have two databases in my Firebird 2.5.3

The first is of 7.5GB and second is of 2.0GB

My server has 4GB of Memory, and sometimes the service FB_INET_SERVER.EXE starts eating my memory from 1.5GB to 2.5GB-3GB of memory and my system slows down..

Same concurrent users, what can i do?