Qualcomm Snapdragon 450 Advantages
Lower TDP (3W vs 6W)
Qualcomm Snapdragon 678 Advantages
Better graphics card performance FLOPS (0.3244 TFLOPS vs 0.1152 TFLOPS )
Larger memory bandwidth (14.9GB/s vs 7.46GB/s)
Higher Frequency (2200MHz vs 1800MHz)
More modern manufacturing process (11nm vs 14nm)
Released 3 years and 6 months late