Comparison of ASRock Radeon RX 6600 Challenger D video card vs GIGABYTE Radeon RX 6900 XT Gaming OC 16G 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 GIGABYTE Radeon RX 6900 XT Gaming OC 16G runs at 1.875 GHz+ 3 % base clock speed and has 16 GB of GDDR6 memory. The TDP of the first video card is 132 W, and the second is 340 W+ 13 %. Compare the table of benchmark results to find out which graphic card is better.