I have a scene where I'm caching a vellum grains simulation to a disk cache. I'm having trouble understanding why it takes so long. When I cache the simulation to ram in the viewport each frame takes about 15 seconds, however when I drop a File Cache SOP and save it to my hard drive each frame seems to take about 3 minutes. Could someone explain why this may be? I have tried saving to another drive and it didn't help.