Comparison of XFX Radeon RX 590 Fatboy 8GB video card vs PowerColor Red Devil Radeon RX 6800 XT 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 PowerColor Red Devil Radeon RX 6800 XT runs at 1.900 GHz+ 4 % base clock speed and has 16 GB of GDDR6 memory. The TDP of the first video card is 225 W, and the second is 300 W. Compare the table of benchmark results to find out which graphic card is better.