Comparison of GIGABYTE Radeon RX 6800 XT video card vs PowerColor Red Devil Radeon RX 7900 XT video card by specs and benchmarks. GIGABYTE Radeon RX 6800 XT runs at 1.825 GHz base clock speed and has 16 GB of GDDR6 memory, while video card PowerColor Red Devil Radeon RX 7900 XT runs at 1.825 GHz base clock speed and has 20 GB of GDDR6 memory. The weight is different, 1500 g vs --. The TDP of the first video card is 300 W, and the second is 300 W . Compare the benchmark results to find out which video card is better.