How long will a single GTX 770/780 last me on 1080p?

[Nada190]

How long can a single GTX 770 or 780 last me on 1080p?

I will give up at medium-low settings, not all the way down but almost.

 

[VincentP]

GTX 770 will give you ultra settings at 1080P.
Crysis 3 is the most demanding game at the moment, the GTX 770 will outperform the GTX 680 in this chart:
http://www.tomshardware.com/reviews/crysis-3-performance-benchmark-gaming,3451-6.html

It will be a number of years before anything is released that would require you to go down to medium settings. We don't really know what upcoming requirements will be, but I expect this to be at least 2 years as games are generally developed for the hardware available when they are released.