Some news about GeeXLab 0.15.0.1. This version is available for Windows 64-bit only.
http://www.geeks3d.com/hacklab/20170518/geexlab-0-15-0-1-and-two-sided-lighting/
(http://www.geeks3d.com/public/jegx/2017q2/pny/nvidia-quadro-p5000-geexlab-double-side-lighting.jpg)