If it isn't a DMX4500, you could add DAs.  If you are running RAID5 or RAID6, you could find a way to migrate to mirrored which would take a load off of the DAs.
I installed SPA and realised that all our DA directors are > 80% utilization. One good thing is that they are all balanced at 80%.  These stay up at >65% all the time. All other parameters are below 50.   If a few DA's were hot and some cold we could balance the load on these and get normal. What is the resolution in this case?
DMX-4 performance