So I just purchased a gopro hero 4 black. All is good until I try to record above 60fps. My playback on my iMac is really choppy. Here are the specs on what I have. 3.2 GHZ I5 8GB RAM Graphics card is NVIDIA GeForce GT 755M 1024 MB. I'm really bummed cause I specifically chose the hero 4 black over the silver only so I could record above 60fps but thats where I am stuck at now. Is my mac the problem?