Tessellation on material using virtual runtime texture over a landscape nukes performance

I have a landscape in my level that I want to put a pile of snow over. I want to control the amount of snow as well as provide tire tracks when I roll over them, so I have a material with tessellation using a virtual runtime texture. When I set the landscape material to the snow, the performance drops significantly. It works, but I need to find out why the performance is so bad. Any suggestions? Thanks!