Comparison of MSI Radeon RX 580 Mech 2 8G OC video card vs Sapphire Toxic Radeon RX 6900 XT Limited Edition video card by specifications and benchmarks. MSI Radeon RX 580 Mech 2 8G OC runs at 1.257 GHz base clock speed and has 8 GB of GDDR5 memory, while video card Sapphire Toxic Radeon RX 6900 XT Limited Edition runs at 1.825 GHz base clock speed and has 16 GB of GDDR6 memory. The TDP of the first video card is 185 W, and the second is 400 W+ 33 %. Compare the table of benchmark results to find out which graphic card is better.