Comparison of ASRock Radeon RX 6600 Challenger D video card vs KFA2 GeForce GTX 1660 Prodigy video card by specifications and benchmarks. ASRock Radeon RX 6600 Challenger D runs at 1.626 GHz base clock speed and has 8 GB of GDDR6 memory, while video card KFA2 GeForce GTX 1660 Prodigy runs at 1.530 GHz base clock speed and has 6 GB of GDDR5 memory. The TDP of the first video card is 132 W, and the second is 120 W. Compare the table of benchmark results to find out which graphic card is better.