Comparison of XFX Speedster MERC 310 Radeon RX 7900 XT video card vs PowerColor Red Dragon Radeon RX 6800 XT video card by specifications and benchmarks. XFX Speedster MERC 310 Radeon RX 7900 XT runs at 1.500 GHz base clock speed and has 20 GB of GDDR6 memory, while video card PowerColor Red Dragon 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 300 W, and the second is 300 W. Compare the table of benchmark results to find out which graphic card is better.