Comparison of PowerColor Red Devil Radeon RX 6900 XT video card vs ZOTAC Gaming GeForce RTX 3090 AMP Extreme Holo video card by specifications and benchmarks. PowerColor Red Devil Radeon RX 6900 XT runs at 1.825 GHz base clock speed and has 16 GB of GDDR6 memory, while video card ZOTAC Gaming GeForce RTX 3090 AMP Extreme Holo 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 420 W+ 20 %. Compare the table of benchmark results to find out which graphic card is better.