Putting this here for reference in case anyone else has a similar issue:
http://forum.mikrotik.com/t/v7-15beta-testing-is-released/174120/363
I originally reported high CPU usage on an RB750Gr3 in the post above. I recently noticed the same on a brand new CRS310-8G+2S+
It turns out it was my own fault. Neither of these devices have a console port but in both these devices I had used a USB console cable in the USB port for console access. Once I was finished I had left the USB console cable in place. This was the cause of my high CPU usage for the management process.
Might help someone out or at least if you are using the USB port for console access and you see high CPU access now you know why!