Qualcomm Snapdragon 660 Advantages
Lower TDP (5W vs 6W)
HiSilicon Kirin 990 5G Advantages
Better graphics card performance FLOPS (0.6912 TFLOPS vs 0.2176 TFLOPS )
Larger memory bandwidth (34.1GB/s vs 13.9GB/s)
Higher Frequency (2860MHz vs 2200MHz)
More modern manufacturing process (7nm vs 14nm)
Released 2 years and 5 months late