Comparison of Sapphire Nitro+ Radeon RX 6900 XT video card vs Gainward GeForce RTX 3070 Phantom+ GS LHR video card by specifications and benchmarks. Sapphire Nitro+ 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 LHR runs at 1.500 GHz base clock speed and has 8 GB of GDDR6 memory. The TDP of the first video card is 340 W+ 13 %, and the second is 270 W+ 23 %. Compare the table of benchmark results to find out which graphic card is better.