Comparison of Sapphire Nitro+ Radeon RX 5500 XT 8G SE video card vs XFX Speedster MERC 319 Radeon RX 6800 XT Black Gaming video card by specifications and benchmarks. Sapphire Nitro+ Radeon RX 5500 XT 8G SE runs at 1.607 GHz base clock speed and has 8 GB of GDDR6 memory, while video card XFX Speedster MERC 319 Radeon RX 6800 XT Black Gaming runs at 1.925 GHz+ 5 % base clock speed and has 16 GB of GDDR6 memory. The TDP of the first video card is 135 W+ 4 %, and the second is 300 W. Compare the table of benchmark results to find out which graphic card is better.