Comparison of Sapphire Radeon RX 6900 XT video card vs ASUS TUF Gaming GeForce RTX 3090 video card by specifications and benchmarks. Sapphire Radeon RX 6900 XT runs at 1.825 GHz base clock speed and has 16 GB of GDDR6 memory, while video card ASUS TUF Gaming GeForce RTX 3090 runs at 1.395 GHz base clock speed and has 24 GB of GDDR6X memory. The TDP of the first video card is 300 W, and the second is 350 W. Compare the table of benchmark results to find out which graphic card is better.