MediaTek Helio P65 Advantages
More modern manufacturing process (12nm vs 14nm)
Released 2 years and 10 months late
Qualcomm Snapdragon 821 Advantages
Better graphics card performance FLOPS (0.3343 TFLOPS vs 0.0787 TFLOPS )
Larger memory bandwidth (29.8GB/s vs 13.41GB/s)
Higher Frequency (2342MHz vs 2000MHz)