ac450 controller load average 90%
As an estimate, do an ANPER on the controller and look at the detailed system load for each task. Deleting TTD logs will remove the CPU load coming from tasks DCTA100, DCTA500 and DCTA600.
Of course, if you havent already replaced the TTD logs with 800 xA trends you will need to allow for increased comms. But generally 800xA logging is supposed to be more efficient.