AMD Radeon R9 270 's Advantages
Released 7 months late
Lower TDP (150W vs 375W)
AMD Radeon HD 8990 OEM 's Advantages
Boost Clock has increased by 8% (1000MHz vs 925MHz)
More VRAM (3GB vs 2GB)
Larger VRAM bandwidth (288.0GB/s vs 179.2GB/s)
768 additional rendering cores