AMD Radeon HD 7990 's Advantages
Larger VRAM bandwidth (288.0GB/s vs 112.0GB/s)
1024 additional rendering cores
AMD Radeon RX 560 's Advantages
Released 4 years late
Boost Clock has increased by 28% (1275MHz vs 1000MHz)
More VRAM (4GB vs 3GB)
Lower TDP (75W vs 375W)