Comparison of XFX Radeon RX 580 GTS Black Edition 8GB video card vs PowerColor Fighter Radeon RX 6600 XT video card by specifications and benchmarks. XFX Radeon RX 580 GTS Black Edition 8GB runs at 1.257 GHz base clock speed and has 8 GB of GDDR5 memory, while video card PowerColor Fighter Radeon RX 6600 XT runs at 1.968 GHz base clock speed and has 8 GB of GDDR6 memory. The TDP of the first video card is 185 W, and the second is 160 W. Compare the table of benchmark results to find out which graphic card is better.