Comparison of PowerColor Red Devil Radeon RX 6600 XT video card vs ASRock Radeon RX 6800 Phantom Gaming D 16G OC video card by specifications and benchmarks. PowerColor Red Devil Radeon RX 6600 XT runs at 2.188 GHz+ 11 % base clock speed and has 8 GB of GDDR6 memory, while video card ASRock Radeon RX 6800 Phantom Gaming D 16G OC runs at 1.850 GHz+ 9 % base clock speed and has 16 GB of GDDR6 memory. The TDP of the first video card is 160 W, and the second is 250 W. Compare the table of benchmark results to find out which graphic card is better.