Which graphic card is better? 1.gtx 860m with 4 gb gddr5 2.gtx 960m with 4 gb ddr3?

I want to buy a laptop called lenovo y50 and it has some models i'm thinking about two models(J & A 2015) Model J has Nvidia gtx 860m graphic card with 4 gb gddr5 graphic memory and model A 2015 has gtx 960 with 4 gb ddr3 graphic memory and now i want to know which graphic card is better?