At present 54 cron jobs per hour (1 at 2 minutes, 1 at 5 min, 1 at 10 min, 1 at 15 min, and 1 at 30 minutes).
Just out of curiosity are the crons set to run at those exact times. 2 minutes after the hour, 5 minutes after the hour, 10 minutes after the hour ect. If that is the case at the 30 minute mark you are trying to run all 5 jobs at the same time and at the 10 minute mark you are running 3 jobs at the same time. Or are they set up to start at different minutes? For example, the 2 minute cron set at 0 minutes then run at 0,2,4,6,8,10,ect, the 5 minute cron set to start at one minute after the hour then run at 1,6,11,16,21 ect. The 10 minute set at 3 minutes after the hour which then would run at 3,13,23,33 ect......
Doug