Well, you could try increasing the default "Info" threshold value for MaxProcess within the web UI (Click on Configuration tab, then, expand PureDisk ContentRouter, Default ValueSet for PureDisk ContentRouter, Sections, Monitor and then edit MaxProcess, default value is ALL OS:500 600 700 0 1 ...change to: 600 700 800 0 1)
....Good move on your part on spreading out the backup schedules.....but you also might try limiting the # of streams your PureDisk client agents are sending -and- check what your 'Max concurrent jobs' value is on the NBU Storage Units related to PDDO. If the Max Concurrent Jobs is some obscenely high value (I ran into problems with this set to 50! in my busy environment with max jobs per client at 99!), try reducing that max concurrent jobs value to say 12 for a night or weekend to see if the problem becomes less severe or even disappears. You should also set pd.conf on your NBU mediasvrs to use compression.
You might look at other things for performance...like what is the throughput on your PD client bkups and the NBU bkups? If it's bad, then more and more streams are going to pile up and run concurrently....try tweaking things. PD6.5.1 upgrade includes a tcp_tune.sh script that helps on the PDOS side. There is also some network performance tuning stuff in the PureDisk best practices guide (TN319449).