Comparison of MSI Radeon RX 6600 XT MECH 2X 8G OCV1 video card vs GIGABYTE Radeon RX 6900 XT 16G video card by specifications and benchmarks. MSI Radeon RX 6600 XT MECH 2X 8G OCV1 runs at 1.968 GHz base clock speed and has 8 GB of GDDR6 memory, while video card GIGABYTE Radeon RX 6900 XT 16G runs at 1.825 GHz base clock speed and has 16 GB of GDDR6 memory. The TDP of the first video card is 160 W, and the second is 300 W. Compare the table of benchmark results to find out which graphic card is better.