i5-6200U with geforce 920M. 12 gb ram.
Originally I was encoding at 4000 kbits, 1066x800 output resolution, 30 fps. On the advice of Staiain, I dropped that to 1500 kbits, 848x480 60 fps. Using QVS encoder.
That really helped, but it's still making a noticeable impact, enough that my scores are definitely still affected.