Comparison of XFX Speedster MERC 319 Radeon RX 6900 XT Ultra Gaming video card vs ZOTAC GAMING GeForce RTX 2080 Twin Fan video card by specifications and benchmarks. XFX Speedster MERC 319 Radeon RX 6900 XT Ultra Gaming runs at 1.925 GHz+ 5 % base clock speed and has 16 GB of GDDR6 memory, while video card ZOTAC GAMING GeForce RTX 2080 Twin Fan runs at 1.515 GHz base clock speed and has 8 GB of GDDR6 memory. The TDP of the first video card is 300 W, and the second is 215 W. Compare the table of benchmark results to find out which graphic card is better.