Desktop wise usually the screen gets to big so you cant see all of the desktop. Thou gaming wise you can use these depending one which team your on:
DSR (
Dynamic Super Resolution) : NVidia's own kind SMAA, you set a higher resolution and the GPU then down samples it to your native resolution in form an antialiasing but with a performance hit.
http://www.geforce.co.uk/hardware/technology/dsr/technology
VSR (
Virtual Super Resolution): AMD's reply to NVidias DSR and practically does the same thing but only on their hardware of course.
http://www.amd.com/en-us/innovations/software-technologies/technologies-gaming/vsr
I use DSR with my GTX 970 on not very GPU demanding games so I can use up my GPU's horse power. I have used it on Dishonoured and it made a huge difference, my frame-rate stayed at a smooth 60fps with DSR, if I use DSR I run it at x4 of my display which is 4K 3840×2160. I'm amazed my GPU could easily handle it, the MSI GTX 970 4GB is the most power card I have ever owned.
On some games though it is not recommended you use DSR or VSR as your asking a GPU to render pretty much the equivalent of four 1080p displays.
Its amazing when you use it on older games.