Comparison of Biostar Radeon RX Vega 56 8G video card vs Sapphire Radeon RX Vega 64 video card by specifications and benchmarks. Biostar Radeon RX Vega 56 8G runs at 1.156 GHz base clock speed and has 8 GB of HBM2 memory, while video card Sapphire Radeon RX Vega 64 runs at 1.247 GHz base clock speed and has 8 GB of HBM2 memory. The TDP of the first video card is 210 W, and the second is 295 W. Compare the table of benchmark results to find out which graphic card is better.