AMD Radeon RX 580 's Advantages
Released 3 years and 4 months late
Boost Clock has increased by 44% (1340MHz vs 930MHz)
More VRAM (8GB vs 2GB)
Larger VRAM bandwidth (256.0GB/s vs 73.60GB/s)
1792 additional rendering cores
AMD Radeon R9 255 OEM 's Advantages
Lower TDP (65W vs 185W)