Milerky2 This person is a Verified Professional
This person is a verified professional.

First things first, Make sure your BIOS is up to date, as there may be features that were not in the first revision. What I did in a very similar situation, was turn off transcoding per camera channel. This brought my CPU usage down significantly.

Under the Video tab in each camera preferences, select "Limit decoding unless required" This will stop the PC from decoding all the streams in realtime. 

I run 38 cameras on an i7-4770 at 25-34% CPU with these settings.