Comparison of XFX Radeon RX 590 Fatboy 8GB video card vs Sapphire Radeon RX Vega 64 video card by specifications and benchmarks. XFX Radeon RX 590 Fatboy 8GB runs at 1.469 GHz base clock speed and has 8 GB of GDDR5 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 225 W, and the second is 295 W. Compare the table of benchmark results to find out which graphic card is better.