Yes, with regards to performance, Nvidia GeForce GTX 1660 Ti outperforms, GeForce GTX 980 Ti by 10.0%.
The GTX 1660 Ti is more energy-efficient considering its peformance, consuming 120 watts to produce 3DMark score of 6373. By comparing its benchmark score to its power consumption, we get an efficiency score of 53.1. GTX 980 Ti's efficiency score is 23.2, 129.2% lower, making GTX 1660 Ti the smarter choice in terms of power consumption.
When considering value for money, GTX 1660 Ti offers a better deal than, GeForce GTX 980 Ti by 42.9%.