Samsung Exynos 990 Advantages
Better graphics card performance FLOPS (1.126 TFLOPS vs 0.0998 TFLOPS )
Larger memory bandwidth (44GB/s vs 12.8GB/s)
Higher Frequency (2730MHz vs 2100MHz)
More modern manufacturing process (7nm vs 20nm)
Released 4 years and 5 months late
MediaTek Helio X20 Advantages
Lower TDP (5W vs 9W)