Well I did RMA my gpu, but the sent it back saying it was perfectly fine, and that I should upgrade to a 750watt psu. I finally got around to doing that but the problem still persists. Waiting to hear what manufacturer suggests next
Also, the one other place I encounter errors is when editing complex 3d models. It tends to crash in a similar manner, so its probably not just the UE4 engine. I guess ill try a new MOBO/CPU.