Yes, with regards to performance, Nvidia GeForce GTX 1660 SUPER outperforms, Radeon RX 5500 XT by 25.1% in 3Dmark benchmark.
The GTX 1660 SUPER is more energy-efficient considering its performance, having power consumption of 125 watts and a 3DMark score of 6078. By comparing its benchmark score to its power consumption, we get an efficiency score of 49. RX 5500 XT's efficiency score is 37 .So GTX 1660 SUPER leads by 32.4%, making it the smarter choice in terms of power consumption.
GTX 1660 SUPER price to performance rating is lower than RX 5500 XT's. RX 5500 XT offers 28.6% better value fo money.