My largest classes never had more than 16 students. They regularly would all try to upload (from 1 to 10 MB depending on assignment) at the last minute just as a classroom session ended on the day an assignment was due. My first couple of servers were old cast off desktops so we tested by deliberately trying to click submit at the same time just to see what problems we might have. Also did the same when I installed a "good"server. The ONLY time we ever had any problems it was caused by modsecurity not liking something about the file, maybe 1 file out of 5 classes on any given assignment. With modsecurity turned off temporarily when uploading, we never had an upload failure. Then it was just wait for the delay caused by everyone sharing the 10 Mbps pipeline going to the server at my house.
by AL Rachels.