Comparison of Sapphire Radeon RX 6900 XT video card vs ZOTAC GeForce GTX 1080 Ti AMP Edition 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 ZOTAC GeForce GTX 1080 Ti AMP Edition runs at 1.569 GHz+ 6 % base clock speed and has 11 GB of GDDR5X memory. The TDP of the first video card is 300 W, and the second is 270 W+ 8 %. Compare the table of benchmark results to find out which graphic card is better.