Qualcomm Snapdragon 450 Advantages
Lower TDP (3W vs 11W)
Released 10 months late
Qualcomm Snapdragon 821 Advantages
Better graphics card performance FLOPS (0.3343 TFLOPS vs 0.1152 TFLOPS )
Larger memory bandwidth (29.8GB/s vs 7.46GB/s)
Higher Frequency (2342MHz vs 1800MHz)