Chosen Solution
I have 24" iMac (2009) It had The graphics card problem, I changed it to a second hand AMD 2GB graphics card (same model graphics card & tested) display is OK. But, the new version of FinalCut Pro is only playing in slow motion and the video is choppy (not smooth). I also updated to the newest version. Any help is greatly appreciated. Update (12/02/2017) 4k video- one minutes Correct model: iMac 27" mid 2011Processor 3.4 Ghz i7Memory 8 GB 1333 MHz DDR3Graphics AMD Radeon HD 6970M 2048 MBSSD - 500 GB Samsung 850 EVO (new disk 01 - OS)HDD - 1 TB (disk 02 - Data) MacOS Sierra
I would max the system out to 16 GB of RAM for starters. On your boot drive (SSD) how much space is free? You should have 1/3 of it free.
