Working on a simple vray scene, 80% proxies, 38mb filesize, some trees from Evermotion Vol 85. When you press render, DANG!!
Either it halt at the beginning of render or max crashed at the end of it, you scene probably haunted by the evil hair&fur!
After I removed the hair&fur (don't forget remove in the Effects panel as well), the RAM consumption goes down from 6GB to 2GB. Yes, 4GB, it is 4GB!!
The hair&fur when use improperly with Vray, it's really gonna kill. However, it doesn't mean you can't use it at all. Check this solution out, it may save you some time from hunting down the hair&fur in your scene:
Rendering Hair&Fur modifier with Vray