Comparison of ZOTAC GeForce GTX 1080 Ti AMP Extreme video card vs Colorful GeForce GTX 1660 Ti SI 6G-V video card by specifications and benchmarks. ZOTAC GeForce GTX 1080 Ti AMP Extreme runs at 1.645 GHz+ 11 % base clock speed and has 11 GB of GDDR5X memory, while video card Colorful GeForce GTX 1660 Ti SI 6G-V runs at 1.500 GHz base clock speed and has 6 GB of GDDR6 memory. The TDP of the first video card is 320 W+ 28 %, and the second is 120 W. Compare the table of benchmark results to find out which graphic card is better.