Redmi Note 4 Vs. Redmi Note 3 Performance comparison [Architectural]

Redmi Note 4 is launched in India.

Few people, including me, have doubts why Xiaomi uses a weak processor with Redmi Note 4 i.e. 625 rather than 650 as in Redmi Note 3 or better. I was also wondering why Hugo has not discussed the benchmark results and comparison with other models like he has done in Redmi Note 3. This thread explains every possible technical detail about the two processors and comparison from an architectural perspective, as I don't have the actual device.

Qualcomm Snapdragon 625  vs. Snapdragon 650

Snapdragon 625: The Qualcomm Snapdragon 625 CPU has 8 core(s), resulting in extremely efficient multi-tasking when compared to dual-core processors. Maximum clock achievable by the CPU is 2 GHz.This processor is based on the Reduced Instruction Set Computing (RISC) design strategy enabling instructions to execute faster, as opposed to the Complex Instruction Set Computing (CISC) design strategy, which is generally slower at executing due to lengthy instructions and not good for pipelining due to different instruction lengths.

Snapdragon 650 : The Qualcomm Snapdragon 650 has a CPU that performs slightly higher than average. Generally, a system on a chip has an average clock speed of 1.3 GHz. The Snapdragon 650 is also based on the Reduced Instruction Set Computing (RISC), which has a maximum clock speed of 1.8 GHz and is a Hexacore(6) CPU.

Architectural Comparison

Properties	Snapdragon 625 (Redmi Note 4)	Snapdragon 650 (Redmi Note 3)
CPU clock speed	2 GHz	1.8 GHz
CPU cores	8 Cores	6 Cores
Processor	Eight ARM Cortex A53	2 x A72 + 4 x A53
CPU structure	RISC	RISC
Semiconductor technology	CMOS	CMOS
Architecture	14nm (new, cooler, battery efficient)	28nm (Older, Heats up, Eats more battery)
No. of CPU pipeline            stages	Avg - 7.667 Max - 16	Avg - 7.667 Max - 16
Cache	L1 instruction cache - 35.11kb/core L1 data cache - 23.13kb/core L2 cache - 1024kb/core	L1 instruction cache - 35.11kb/core L1 data cache - 23.13kb/core L2 cache - 1037kb/core
Word length	64 bit	64 bit
Data bus	32 bit	32 bit
GPU	Adreno 506	Adreno 510
Advance graphics API	OpenGL ES 3.1	------
DSP type	Qualcomm Hexagon 546	Qualcomm Hexagon

performance (due to heavy usage)	not as fast as 650	faster
battery performance	better	not as good as 625

Final Verdict:

• 625 has eight A53 cores, SD 650 has 2 cortex A72 cores out of the six cores and remaining are A53 but in general usage, A72 performs better than A53 for single threaded task, i.e most apps, system functions use one or two CPU cores majority of their time hence they have an edge here.
• The Adreno 510 GPU which is better than 506 in the 625 and hence better graphics performance.
• For battery life and reasonable performance (snapdragon 625 should be preferred)
• The snapdragon 625 is built on 14nm architecture which is the best and the most efficient architecture, processors with multiple cores can hit higher clock speeds without overheating and draining the battery quickly with 14nm hence battery life is better and no heat ups with 625 since it is A53 cores at 2GHZ , while 650 has 28nm architecture which is bigger and drains battery faster.
• That's why Redmi Note 3 has better performance in computation and Redmi Note 4 better in Battery. So it's you to choose which device is preferable for you.

For More info about the benchmark results of Redmi Note 3 and Redmi Note 4 visit Digit.