So... I have had NO problem with editing and playback 4k videos. I have 24gig Ram. 6 core processor, etc. all of a sudden, ALL of my videos are playing back choppy like crazy! I have not installed any new software or anything like that. In fact, I pretty much ONLY use that computer for editing and processing videos. I did a restore to several days ago when it last ran perfectly. No change. Any of you computer guys have any ideas what I should be looking for to fix it? I did run a full system virus scan and made sure my video driver is current.