Comparison of XFX Speedster MERC 319 Radeon RX 6800 Black Gaming video card vs Gainward GeForce RTX 3090 Phantom video card by specifications and benchmarks. XFX Speedster MERC 319 Radeon RX 6800 Black Gaming runs at 1.850 GHz+ 9 % base clock speed and has 16 GB of GDDR6 memory, while video card Gainward GeForce RTX 3090 Phantom runs at 1.395 GHz base clock speed and has 24 GB of GDDR6X memory. The TDP of the first video card is 250 W, and the second is 370 W+ 6 %. Compare the table of benchmark results to find out which graphic card is better.