Rhino 5 VRay 2.0 crashes when rendering file

I’m trying to render a pretty large file on bootcamp but Rhino crashes before starting the render. I presume its because I dont have enough RAM but I have 16gb and it only uses a maximum of 8.1 (says theres an available 7.7 left).

I did a test render of a 98.1mb file at 1600x1200 and a max of 5.7gb of memory was used.

I then tried the file I want which is 258mb. 4.9gb were used when just running the file and then rhino crashed about 15min of processing geometry table, then suddenly jumping to 100% rendered (no image of the render) at 8.1gb.

I’m running rhino and VRay on bootcamp at an 80/20 split OS to Windows 10 on a macbook pro.

Is its the RAM thats causing the problem and if so, can I access that extra 7gb?