Comparison of GIGABYTE GeForce GTX 1080 D5X 8G video card vs KFA2 GeForce GTX 1660 Ti Prodigy video card by specifications and benchmarks. GIGABYTE GeForce GTX 1080 D5X 8G runs at 1.607 GHz base clock speed and has 8 GB of GDDR5X memory, while video card KFA2 GeForce GTX 1660 Ti Prodigy runs at 1.500 GHz base clock speed and has 6 GB of GDDR6 memory. The TDP of the first video card is 180 W, and the second is 120 W. Compare the table of benchmark results to find out which graphic card is better.