Comparison of GIGABYTE Radeon RX 580 Gaming 8G MI video card vs ASRock Phantom Gaming X Radeon RX Vega 56 video card by specifications and benchmarks. GIGABYTE Radeon RX 580 Gaming 8G MI runs at 1.257 GHz base clock speed and has 8 GB of GDDR5 memory, while video card ASRock Phantom Gaming X Radeon RX Vega 56 runs at 1.156 GHz base clock speed and has 8 GB of HBM2 memory. The TDP of the first video card is 185 W, and the second is 210 W. Compare the table of benchmark results to find out which graphic card is better.