I am currently doing a video project with my non-retina mid 2012 Macbook Pro 13". It has the i5 2.5ghz dual core. I have upgraded it with two 4gb RAMs, and there is just the 500gb HDD for storage. Now I know it's not super fast but I want to edit 4k videos or at least be capable of downscaling 4k video clips and produce a 1080 video with Premiere Pro CC 2017. I have video clips that are 120p 1080 and 60fps 4K. For the 120fps 1080 videos, I want to slow down the clips for some slow motion shots. So far, my MBP can play the video clips smoothly after loading a few seconds but when put into Premiere Pro, they get super slow in playback. So my question is, if I remove the optical drive and move my HDD there, buy a 250 Samsung 850 EVO SSD and make a fushion drive. Will I be able to edit the video clips and playback smoothly. If not, what should I do?