I had looked at that thread earlier on... SSH seems to be fairly snappy, and not really an issue here. My major concern is what it would do to overall performance with all of our switches doing 5 minute cycles of 30%-40% load on top of what actual loading would be... I had also done some latency testing many months ago when I first observed this issue that showed 2 known workstations on the same switch running post 16.03 would nearly double the round trip ping time during these spikes. I've been looking for the screen caps of that testing, but I may have to redo it....
Looking at it from another angle, based on this older article regarding a possible L2 Loop causing high CPU about every 3 minutes, and this one regarding SNMP monitoring causinghigh CPU (I monitor with Airwave), I decided to test the switch completely off network using the system monitor in the nextgen web interface, which provides about 2 hours of visible history. The switch was on the network with a single port all night, I logged into the web interface to check status, and then immediately unplugged the one connected port. I let it run for an hour with nothing plugged in but power, and then reconnected to the network, logged in, and took this screen capture of the system monitor history graph: (bigger version attached below)
It turns out that even with no network connection whatsoever, the switch is still showing 30% peaks about every 5 minutes. The background use is gone, and it's dead flat inbetween, but the peaks are there like clockwork.
I also recall a couple of articles regarding some versions screaming out to aruba central at regular intervals, but according to the switch, all of the settings I can find regarding that are set to disabled. so, another piece of the puzzle....