The only issue I've encountered while gaming at 4K is that a handful of older games (I've tested around a hundred, so far) seem to want to run at 24 Hz, if at 3840 * 2160; if you encounter this issue, simply create a custom resolution of 3838 * 2159 @ 60 Hz, then disable scaling (to keep it pixel-perfect); they'll then run at 60 fps, assuming that you have the hardware (I'm using two GTX 970s, which are surprisingly powerful enough for most of my collection at 4K/60/maxed [some with additional SSAA, etc.]). (Let me tell you this: there is absolutely no going back to 1080p gaming after seeing this, my friends.) 🙂