Yes, with regards to performance, Nvidia GeForce GTX 1080 outperforms, GeForce GTX 1070 Ti by 10.6%.
The GTX 1080 is more energy-efficient considering its peformance, consuming 180 watts to produce 3DMark score of 7570. By comparing its benchmark score to its power consumption, we get an efficiency score of 42.1. GTX 1070 Ti's efficiency score is 38.0, 10.6% lower, making GTX 1080 the smarter choice in terms of power consumption.
When considering value for money, GTX 1080 offers a better deal than, GeForce GTX 1070 Ti by 63.6%. Here is more in depth overview of the price and used prices of GTX 1080 Price History and GTX 1070 Ti Price History