Tried 3 screens independently, nVidia became terminally confised. I've got three, one plugged into one port, and two more ona toggle switch connected to another port. Doesn't want to play any other way. I'll get around to removing all drivers are reinstalling at some point, as I only need two screens at any one time - the toggle between other two is ok, because one displays more colours than the other, which is useful for video rendering. About four times as fast rendering, temps are hovering stable about 62 degrees at full load for many hours, I don't think it needs heatsink compound replacing. Sometimes faster, depending on the type of rendering.