My son has a macbook air. We got him an external display and attached it with a j5Create HDMI and Hub USB 3.0 multi adapter (model JUH450). The display looks great except the frames per second went from mid 70's on the mac to 15-20 using the big display. Is there a setting or something I need to adjust for it not to have this performance degradation. Help....major downer on Christmas morning. Thanks.
If the problem is in Minecraft, you should adjust the configurations. Try lowering The chunks loaded per distance, graphics set to fast, and clouds off.
So basically, I'm stupid.