Hi, So I've been testing a really heavy duty 4K project - lots of 2D and 3D titles, gaussian blur - on a Mac Pro 12 core, D700, iMac 5K late 2015 395X max out + flash and my old 15" MBP 750M. Mac Pro - 17+ effects in real time iMac 5K - 4-5 effects lots of dropped frames MacBook Pro 15" Late 2013 - 8-10 effects in real time I had a look at the CPU and GPU usage and: iMac 5K - 25% CPU usage & 5% GPU usage with an average of 5FPS when playing the project (used iStats to measure this) MacBook Pro 15" Late 2013 - 155% CPU usage (so one core and 1/2) and 80% GPU usage @49-54FPS. Not sure why but FCP seems to not fully utilize the CPU and GPU of the 5K iMac. Tried deleting all preferences, made a new account - same results. What do you guys think? Either FCP hasn't been updated to fully utilize the 5K iMac's hardware - really strange since it's been out since November or...idk? Everything else uses my GPU normally and my CPU so really have no idea here Any thoughts?