No, in terms of performance, Nvidia GeForce GTX 1660 Ti is slower than, AMD Radeon RX Vega 56 by -6.3%.
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. RX Vega 56's efficiency score is 32.3, 64.6% 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, Radeon RX Vega 56 by 280.0%. Here is more in depth overview of the price and used prices of GTX 1660 Ti Price History and RX Vega 56 Price History