No, in terms of performance, Nvidia GeForce GTX 1660 is slower than, Nvidia GeForce GTX 1080 Ti by -71.1%.
The GTX 1660 is more energy-efficient considering its peformance, consuming 120 watts to produce 3DMark score of 5454. By comparing its benchmark score to its power consumption, we get an efficiency score of 45.5. GTX 1080 Ti's efficiency score is 37.3, 21.7% lower, making GTX 1660 the smarter choice in terms of power consumption.
When considering value for money, GTX 1660 offers a better deal than, GeForce GTX 1080 Ti by 108.3%. Here is more in depth overview of the price and used prices of GTX 1660 Price History and GTX 1080 Ti Price History