Complex sentence: The school library and some of the other computer rooms utilize a set of terminals which are cheaper then normal computers, the disadvantages, however, are that if someone uses a relatively large program, it can drain speed from other computers.
Split into simpler sentences: The school library and some of the other computer rooms utilize a set of terminals, which are cheaper then normal computers. The main disadvantages is that if someone uses a relatively large program, it can drain speed from other computers.