Hello,
Ive had this issue for a long time now and cannot find a solution.
I have 2 240hz screens both connected directly into GPU with DisplayPort cables. At the start its all fine, I can watch videos and play on fullscreen on the other screen and do whatever, but after a while and I close a game it starts stuttering like crazy, I can feel it on the mouse pointer on the desktop just by dragging it left to right. I recorded a video of it on CS:GO here: https://www.youtube.com/watch?v=44kPD77Ci5g&feature=youtu.be
I used 240hz screen with a 60hz, and it happened there, but I got told it was because of the difference in Hz so windows struggles. Now I bought another 240hz today and it still starts to happen after a while, and the only thing that seems to fix it is by restarting. I run www.testufo.com and it seems to stop at 230 hz but its unstable so it still seem like some Hz issues with the monitors. I am at that stage where that I am willing to pay for a fix if anyone can help me.
Thank you.