Comparison of XFX Speedster MERC 319 Radeon RX 6900 XT Black Gaming V2 video card vs ASRock Phantom Gaming X Radeon VII 16G video card by specifications and benchmarks. XFX Speedster MERC 319 Radeon RX 6900 XT Black Gaming V2 runs at 1.950 GHz+ 7 % base clock speed and has 16 GB of GDDR6 memory, while video card ASRock Phantom Gaming X Radeon VII 16G runs at 1.400 GHz base clock speed and has 16 GB of HBM2 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.