Comparison of Gainward GeForce GTX 1080 Ti Phoenix GS video card vs ZOTAC GAMING GeForce GTX 1660 Twin Fan video card by specifications and benchmarks. Gainward GeForce GTX 1080 Ti Phoenix GS runs at 1.556 GHz+ 5 % base clock speed and has 11 GB of GDDR5X memory, while video card ZOTAC GAMING GeForce GTX 1660 Twin Fan runs at 1.530 GHz base clock speed and has 6 GB of GDDR5 memory. The TDP of the first video card is 250 W, and the second is 120 W. Compare the table of benchmark results to find out which graphic card is better.