Comparison of ASRock Radeon RX 6600 XT Challenger D 8GB OC video card vs GIGABYTE GeForce GTX 1660 GAMING 6G video card by specifications and benchmarks. ASRock Radeon RX 6600 XT Challenger D 8GB OC runs at 2.000 GHz+ 2 % base clock speed and has 8 GB of GDDR6 memory, while video card GIGABYTE GeForce GTX 1660 GAMING 6G runs at 1.530 GHz base clock speed and has 6 GB of GDDR5 memory. The TDP of the first video card is 160 W, and the second is 120 W. Compare the table of benchmark results to find out which graphic card is better.