AMD Radeon Sky 900 's Advantages
More VRAM (3GB vs 2GB)
Larger VRAM bandwidth (240.0GB/s vs 144.2GB/s)
832 additional rendering cores
NVIDIA GeForce GTX 660 Rev. 2 's Advantages
Released 1 years and 6 months late
Boost Clock has increased by 9% (1032MHz vs 950MHz)
Lower TDP (140W vs 300W)