Comparison of XFX Speedster MERC308 Radeon RX 6600 XT BLACK Gaming video card vs Gainward GeForce RTX 2080 Phoenix video card by specifications and benchmarks. XFX Speedster MERC308 Radeon RX 6600 XT BLACK Gaming runs at 2.188 GHz+ 11 % base clock speed and has 8 GB of GDDR6 memory, while video card Gainward GeForce RTX 2080 Phoenix runs at 1.515 GHz base clock speed and has 8 GB of GDDR6 memory. The TDP of the first video card is 160 W, and the second is 215 W. Compare the table of benchmark results to find out which graphic card is better.