If you have any issues with SharePoint 2013 consuming all your CPU on a SQL server process you might want to try this. I have been suffering for 2 days with this and I do not really even know if this is what fixed it, but after changing the Memory allocation on SQL I saw an immediate drop in CPU..
Just make sure there is a Minimum server memory specified for the SQL Instance. This reduced my average SQL server process load on CPU from 30-40% down to around 3% on idle. I saw there were continuous calls to the Distributed Cache Service and OSTIMER processes, but now they are normal again.
Honestly, I don’t know why this worked for me. If by magic it works for you, let me know.