I had an amd fx6300, gtx 660 combo. I decided to upgrade the gpu for a gtx 1060. The problem is that my gaming performance got less stable. I get stutters, tears, lags a lot of times. In games where there are cities with more textures i even have lower fps than with my gtx 660. The cpu can cause this as it is not enough for a gtx 1060 or the gpu can be faulty ? In fortnite the cpu usage was between 70-80% i guess thats totally normal.