I just updated my drive with 15.36.14.64.4080.
Still getting choppy stop/go video in the preview window.
The audio seems to work fine and keeps playing all the way through to the end of the clips in the timeline.
My brother also bought a Sony FDR-AX100. He is running it through his new iMac with 5k retina display.
The computer also has an Intel i5 like mines. I have 12GB of RAM, as opposed to only 8GB in the Mac.
He has no problems with viewing choppy video.
Borgus, I'll have to check tomorrow with my local computer guru when they open. 64MG of dedicated video memory is seems low as you say. Found out that this graphics card has no real video memory, and is actually getting the 64MG from RAM.
Heard I'll have to get into the computers BIOS to make an adjustment, or go with a dedicated video card if there is a PCI express X16 slot available on the motherboard.
Thanks for your help in fixing the grainy video!