AMD Radeon R9 280 's Advantages
Larger VRAM bandwidth (240.0GB/s vs 96.00GB/s)
1280 additional rendering cores
AMD Radeon RX 550X 's Advantages
Released 4 years and 9 months late
Boost Clock has increased by 27% (1183MHz vs 933MHz)
More VRAM (4GB vs 3GB)
Lower TDP (50W vs 200W)