Comparison of XFX Radeon RX 580 GTS XXX Edition 4GB video card vs Gainward GeForce GTX 1660 Pegasus OC video card by specifications and benchmarks. XFX Radeon RX 580 GTS XXX Edition 4GB runs at 1.257 GHz base clock speed and has 4 GB of GDDR5 memory, while video card Gainward GeForce GTX 1660 Pegasus OC runs at 1.530 GHz base clock speed and has 6 GB of GDDR5 memory. The TDP of the first video card is 185 W, and the second is 120 W. Compare the table of benchmark results to find out which graphic card is better.