MediaTek Dimensity 800U Advantages
More modern manufacturing process (7nm vs 10nm)
Released 2 years and 8 months late
Qualcomm Snapdragon 845 Advantages
Better graphics card performance FLOPS (0.727 TFLOPS vs 0.3264 TFLOPS )
Larger memory bandwidth (29.8GB/s vs 17.07GB/s)
Higher Frequency (2800MHz vs 2400MHz)
Lower TDP (9W vs 10W)