HiSilicon Kirin 955 Advantages
Lower TDP (5W vs 6W)
HiSilicon Kirin 990 4G Advantages
Better graphics card performance FLOPS (0.6912 TFLOPS vs 0.1152 TFLOPS )
Higher Frequency (2860MHz vs 2500MHz)
More modern manufacturing process (7nm vs 16nm)
Released 3 years and 6 months late