Never do that. It completely breaks thread flow and context.
And it looks like this may be an issue of VRAM/disk access speed. You need a very good GPU to run smoothly with a 256 resource pack. And the 960M, being a mobile GPU, is not that good.
ah ok thanks! Kind of throws me back though when I can run beautiful games like Rocket League, Black Ops 3, Sonic Generations, etc. smoothly but can't run a 256x resource pack? But then again when there's a block on the edge of your render distance I believe your PC still loads it as a 256x texture which I think they should change in a later update to make the overall game play WAY smoother!