Thanks. Its a 2014, its fine with the 1080 but struggles as soon as it hits the 4k footage. I have an SSD on order and will be looking to move all my data there. Will having the source data on the SSD make a noticeble difference?
What is the source footage? I just ask because recently I had this problem, and it's because I had media from a smartphone and most smartphones shoot variable frame rate, which really screws Premiere up.