With the release of 3ds Max and Maya 2016, is also updated rendering engine Mental Ray to version 3.13. The main changes are Light Importance Sampling, new support for MDL Materials, new Global Illumination "Next" (Prototype), Native Ambient Occlusion Pass, GPU Accelerated, Iray 4, Native UV Tiling, OpenEXR 2.2 Support, new feature Alembicand more!!

 

For info: http://help.autodesk.com/cloudhelp/2016/ENU/mental-ray-docs/mr_docs/manual/index.html