For 1080p or even 1440p , 780 ti would be the better choice. If you want to game on a 4k monitor, then 6gb 780 is the way to go. However if you currently have card from 600 series, I would suggest that you wait for 800 series and x99 platform for having a worthwhile upgrade. My jump from gtx 670 to 780ti wasn't all that impressive. I so wish right now that I could've waited for a gtx titan black (6gb) since I recently got a 4k monitor and 780 ti isn't all that great for it.