Comparison of XFX Speedster MERC 319 Radeon RX 6900 XT Limited Black Gaming video card vs ZOTAC GeForce GTX 1080 Ti AMP Extreme video card by specifications and benchmarks. XFX Speedster MERC 319 Radeon RX 6900 XT Limited Black Gaming runs at 2.150 GHz+ 18 % base clock speed and has 16 GB of GDDR6 memory, while video card ZOTAC GeForce GTX 1080 Ti AMP Extreme runs at 1.645 GHz+ 11 % base clock speed and has 11 GB of GDDR5X memory. The TDP of the first video card is 300 W, and the second is 320 W+ 28 %. Compare the table of benchmark results to find out which graphic card is better.