Cannot set Max Screen Resolution of 2560x1440 with DELL U2711 Monitor

Check the cable and make sure it's Dual Link as the behavior your seeing suggests it is not. The graphics card is listed as having two Dual Link DVI ports so either port should work.

Image from Wikipedia article on DVI.

I had this problem myself, and it was indeed due to not using a DVI dual link cable. And on top of that, the first videocard I tried on didn't support the resolution 2560x1440, but that was at work just to test. At home, I thought to make it quick and just replaced my monitor, and kept the cable I was using for years.

Luckily the monitor comes with a dual-link cable so just hooking that one up should do the trick.

Alternatively (and if possible, my suggestion as well) use a DisplayPort cable.

I have a u2713hm and had the same problem. I am using a DVI-D cable but it was a cheap one so have ordered something more premium, i'll try that when it arrives. In the meantime I managed to get a decent picture by going into the Nvidia control panel > change resolution > customise and dropped the refresh rate 1Hz at a time and testing the new setting. Eventually got a good picture at 40Hz, not perfect for gaming but fine for everything else.

GTX 550ti on Win 10, screen worked perfectly on Win 7 at 60Hz.