Question Is it worth to upgrade my gpu to GTX 1070?

Kurtisdede

Commendable
Jun 10, 2017
72
11
1,565
That'll do just fine, a gtx 1660 ti is roughly twice as better than a 770.
Although that's odd that you're only getting 40 FPS on that. A 770 should be capable of more than that.
Check your CPU and GPU temps while in game and if anything's above 85C, then that's a problem.