Adobe Premiere lagging video playback
My experience is that people that complain about choppy playback have either outdated hardware, or are using very esoteric formats, and/or have a system with a lot of crap on it, that seriously gets in the way of editing. You are definitely not in the first category, I don't know the origin of your clips and the codec used, so you could be in the second category, but most likely you have a polluted system.