I have an i7 3939 cpu, 16GB Ram, GTX 760 4GB ram and can play GH4 4k video on a 1080 timeline in Premier just fine. However, in Hitfilm even with proxy and quarter resolution the playback stutters. My drivers are up to date.
I am using a demo version of Hitfilm pro4. Is there something else that needs to be set? I like the features of the program but may delay my purchase until this works properly.