AMD Radeon R9 M390X 's Advantages
Released 3 years and 2 months late
More VRAM (4GB vs 1024GB)
Larger VRAM bandwidth (160.0GB/s vs 64.00GB/s)
1664 additional rendering cores
NVIDIA GeForce GTX 660M 's Advantages
Boost Clock950MHz
Lower TDP (50W vs 75W)