Comparison of XFX Speedster MERC 319 Radeon RX 6900 XT Black Gaming video card vs PowerColor Radeon RX Vega 64 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 PowerColor Radeon RX Vega 64 runs at 1.247 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 295 W. Compare the table of benchmark results to find out which graphic card is better.