MediaTek Helio G90 Advantages
More modern manufacturing process (12nm vs 14nm)
Lower TDP (5W vs 11W)
Released 3 years and 8 months late
Qualcomm Snapdragon 820 Advantages
Better graphics card performance FLOPS (0.3194 TFLOPS vs 0.2074 TFLOPS )
Higher Frequency (2150MHz vs 2050MHz)