Comparison of PowerColor Radeon RX 6900 XT video card vs Gainward GeForce RTX 3070 Phantom GS video card by specifications and benchmarks. PowerColor Radeon RX 6900 XT runs at 1.825 GHz base clock speed and has 16 GB of GDDR6 memory, while video card Gainward GeForce RTX 3070 Phantom GS runs at 1.500 GHz base clock speed and has 8 GB of GDDR6 memory. The TDP of the first video card is 300 W, and the second is 270 W+ 23 %. Compare the table of benchmark results to find out which graphic card is better.