As far as I can tell that seems to be normal, or at least not something that necessarily trashing the system as ours is running OK.
Last time I filed a TAC case, the tech undid some previous tuning done on 8.0.3 and lower and freed up one CPU from "Monitoring Processes" duty, so it was set to # of CPUs minus one. You may want to have TAC look over your settings and make sure they are still correct for 8.0.4.