Comparison of XFX Speedster MERC 319 Radeon RX 6900 XT Black Gaming video card vs MSI Radeon RX Vega 56 8G video card by specifications and benchmarks. XFX Speedster MERC 319 Radeon RX 6900 XT Black Gaming runs at 1.950 GHz+ 7 % base clock speed and has 16 GB of GDDR6 memory, while video card MSI Radeon RX Vega 56 8G runs at 1.156 GHz base clock speed and has 8 GB of HBM2 memory. The TDP of the first video card is 300 W, and the second is 210 W. Compare the table of benchmark results to find out which graphic card is better.