The computer network at CCNY can be quick at times, and at others it can be terribly slow. Network speed generally depends on where and when you're accessing the Web. The library in the NAC has the largest selection of computers in the school, but they are often the slowest. If you want to use the Internet, you should visit the Rudin Learning Center. This area is not used by many students because few know about it.
The computer lab is one of the few areas on campus that allows students to print (there is a maximum of 17 pages per print click). There are always lines at the lab, so plan accordingly if you're worried about being late to class. If you don't need to print, the best thing to do is bring a laptop and access the WiFi available around campus. Be aware, though, that WiFi signals in classrooms are often weak, especially in the older buildings.