Especially in VR, increase your page file...a lot! I have 16 gigs of RAM and a GTX 1070Ti with 8 Gigs and X-plane was still crashing due to out of memory errors. I looked at my page file on my main drive and it was only at 1 Gig max lol. I changed it to 24 gigs on another SSD and no more crashes and I was able to go from medium object density to max. Also if your boot drive doesn't have enough space left, you can switch the page file to another drive. There are a few tutorials on YouTube on how to do it. Good luck!