If the monitor remains black or flickers, it is my experience on the video card, connection via DisplayPort provided. Previously, I had an ATI Radeon R7 250, this was only with 4096x2160 @ 50Hz, 60Hz monitor, however, remained (at least for me) black. Who a new graphics card should therefore study the websites of the graphics card manufacturer closely examined. While on the ATI homepage was as max. 4096x2160 resolution specified a reference to the max. Refresh rate, however I could not find. Find anything I'm on the home page of nVidia, because here at least for newer graphics cards not only the max. Resolution but also the associated refresh rate is specified.