Unitrends system load spikes beyond warning level | slow, failing backups

Having a few failures on a Unitrends appliance. Checking the load, I see the following:

http://imgur.com/a/tohhg

What could be causing the load to hover in the red all the time, and rocket into low orbit on occasion?

Doing Sunday Full/Master backups, Monday archives, diffs and logs during the week.

The only big jobs are the Full of vCenter (1TB) and the Full of a real metal box (300GB) that both kicked off at 2000 on Sunday. I've staggered them as of now.

The most recent weekend's spike, while still in the red, didn't go to infinity and beyond. I had broken up the SQL backups per-db and staggered them, replacing the previous backup-all-dbs job, on the Friday preceding that smaller spike.

I have also noticed that the backup speed is about 24MB/sec, or 1.4GB/min, though the path from the server rack to the backup appliance is one gigabit switch to another gigabit switch.

Here's what the "Processes" screen looks like:
http://i.imgur.com/BhKoga5.png

Is it normal to have processes taking up 2GB of RAM + 90% or more CPU time?