Comparison of ZOTAC GeForce GTX 1070 Founders Edition video card vs Colorful GeForce GTX 1660 Ti SI 6G-V video card by specifications and benchmarks. ZOTAC GeForce GTX 1070 Founders Edition runs at 1.506 GHz base clock speed and has 8 GB of GDDR5 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 150 W, and the second is 120 W. Compare the table of benchmark results to find out which graphic card is better.