Comparison of GIGABYTE GeForce GTX 1080 Xtreme Gaming 8G video card vs GIGABYTE GeForce GTX 1660 D5 6G video card by specifications and benchmarks. GIGABYTE GeForce GTX 1080 Xtreme Gaming 8G runs at 1.759 GHz+ 9 % base clock speed and has 8 GB of GDDR5X memory, while video card GIGABYTE GeForce GTX 1660 D5 6G runs at 1.530 GHz base clock speed and has 6 GB of GDDR5 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.