Comparison of Sapphire Radeon RX Vega 56 video card vs ZOTAC GeForce GTX 1080 AMP Extreme video card by specifications and benchmarks. Sapphire Radeon RX Vega 56 runs at 1.156 GHz base clock speed and has 8 GB of HBM2 memory, while video card ZOTAC GeForce GTX 1080 AMP Extreme runs at 1.771 GHz+ 10 % base clock speed and has 8 GB of GDDR5X memory. The TDP of the first video card is 210 W, and the second is 270 W+ 50 %. Compare the table of benchmark results to find out which graphic card is better.