Comparison of PowerColor Red Devil Radeon RX 6900 XT Ultimate video card vs ZOTAC GAMING GeForce GTX 1660 Ti 6GB GDDR6 video card by specifications and benchmarks. PowerColor Red Devil Radeon RX 6900 XT Ultimate runs at 1.825 GHz base clock speed and has 16 GB of GDDR6 memory, while video card ZOTAC GAMING GeForce GTX 1660 Ti 6GB GDDR6 runs at 1.500 GHz base clock speed and has 6 GB of GDDR6 memory. The TDP of the first video card is 300 W, and the second is 120 W. Compare the table of benchmark results to find out which graphic card is better.