I bought a used gtx 970 a few months ago and never had any problems with it until I realized it's causing problems when editing in after effects. It wasn't previewing / playing back video properly in my project. It would play video back in half speed (not realtime).I had a 750 ti sc before and it never gave me problems in AE. I just put in an older card, GTS 450, and it plays back fine. So it has to be the card but I have no idea what could be causing it to do this.