What are the processors used in smartphones?

While purchasing the smartphone, we check, probably the 1st thing, the processor. A lot of things depend on the quality of the processor. After all, this is the part of the cell phone which drains the battery power continuously. So, the processor much is the most energy-efficient piece of hardware in any mobile device. So, the processors which are used in our desktop PCs are not suitable for mobile devices. The processor in the mobile devices has to overcome several challenges in its application. Let’s dive into a mobile device try to figure it out that which processor is the best to choose for our requirements.

Challenges in a mobile environment:

The first challenge the processor in mobile device faces is the form factor, it the size of the processor. It is obvious that the processor that is used in a desktop PC can’t fit into mobile devices like smartphones and smart appliances. It has to be very compact and must not include a ‘fan’ for cooling itself. This factor is mostly depending on the technology by which the processor chip has been made. 

Secondly, it must be optimized in terms of power usage. Here comes the important aspect of the architecture of a processor. For a detailed analysis of a processor please visit here. It is found that the RISC based processors are one of the best in this class. 

Watch this video for better understanding the working of a processor:

Thirdly, the connectivity of the processor with other peripheral hardware. This another crucial factor in mobile devices. For example, in cellphones, a processor has to connect with a display, a sound system, a ‘transceiver’ system broadly, though there is other hardware. It is worth mentioning that the ‘transceiver’ the system is a system where both the transmitter and receiver work together to send our voice to and from the cell phone. Now, more the processor is capable of connecting with other hardware, more the processor is useful. The first microprocessor from the intel was capable of connecting with simple input and output devices, but now the modern processors can do much more than the previous processors and take much small space in the device.

There are other challenges but let us not consider them for time being and jump to a comparison of different processors that are used in modern-day processors.

How a processor is used in a mobile device?

In mobile devices the RISC based ARM processors are considered mostly, there are other processors out there, but let’s take the most popular ARM cores. ARM is not a physical processor, rather it is a design by a company ARM holding Ltd. It is highly recommended that one should visit their website and check the different products they provide. So, ARM designs one of the most efficient processor core which is called an Intellectual Property (IP) and sells it to other companies like Qualcomm, Mediatech, Samsung, etc. actually a ton of other companies. Then they use the processor core into their products which they call it a ‘system on a chip’ (SoC). Let’s understand it simply, they purchase the processor design from ARM, use the design to connect it with other hardware like Graphical Processing Unit (GPU, another smaller processor that handles how the graphics of the mobile device should perform), sound system, transceiver, etc. as mentioned before. Up to this, there is no physical device that they produce, all they have a complete design of a system consists of an ARM core, sound, display, transceiver subsystems. AT this stage they send the complete design to another fabrication company they make the processors as per the design made. The output hardware is called a system on a chip (SoC).  So, Qualcomm snapdragon, Mediatech Helio, and even Samsung's Exynos are examples of SoCs. Above them, Samsung has its own fabrication services so, they are able to design and make their own SoC. 

Comparison of hardware used in SoCs for the smartphone application:

The comparison works best when the platform is the same, so for this comparison, the common platform would be 5G. One thing must be kept in mind that this comparison is not a performance comparison. The overall performance of the SoC depends on multiple factors, and only a handful of them is considered here. The true comparison can be done by means of a process which is called a ‘processor benchmark’. Here only hardware comparison is carried out just to show how processors do their job in mobile platforms. The 5G enabled budget centric SoCs are considered here, and the most important comparison will be carried out only in these categories: ARM core, GPU, Memory (RAM) capacity, cellular connectivity (modem), and last but not the least Fab Lab technology. Let’s see them one by one. 

Specification	Qualcomm Snapdragon™ 690 5G	MediaTek Dimensity 720	Samsung Exynos 980
ARM core	Kryo 560 (ARMv8-A 64-bit), Octa-core CPU, Up to 2.0 GHz	Octa-Core: 2x ARM Cortex-A76 up to 2GHz; 6x ARM Cortex-A55 up to 2GHz	2.2GHz Dual-core (Cortex®-A77) + 1.8GHz Hexa-core (Cortex®-A55)
GPU core	Adreno 619L GPU	ARM-Mali G57 MC3	ARM-Mali™-G76 MP5
Memory support	2 x 16-bit, LPDDR4x	LPDDR4X memory up to 2,133MHz	LPDDR4x
Cellular connectivity	5G standalone (SA) and non-standalone (NSA) modes, FDD, TDD • Dynamic Spectrum Sharing • Sub-6 GHz: 100 MHz bandwidth, 4x4 MIMO	5G Up to 2CC 2.34Gbps, SA & NSA, Sub-6GHz, 5G+4G	5G NR Sub-6GHz 2.55Gbps (DL) / 1.28Gbps (UL), EN-DC 3.55Gbps (DL) / 1.38Gbps (UL), LTE Cat.16 5CA 1Gbps (DL) / Cat.18 2CA 200Mbps (UL)
Fab Technology	8nm	23 nm	8nm FinFET

We clearly see from the very 1^st line of the table that, every SoC contains one or more ARM processor cores. Now, depending upon the core design the SoC offers different sets of performance levels. Again, Mali GPUs are designed by ARM whereas Ardeno GPU is found only in snapdragon SoCs and those are designed by Qualcomm. All three products support Low power DDR 4x memory support for the CPU. As far as the fabrication technology is concerned, both Snapdragon & Exynos SoCs are built on 8 nm, whereas the Dimensity is built on 23 nm. Which in turn indicate that both Qualcomm & Exynos should have better performance as compared to MediaTek Dimensity SoC. But again, it cannot be confirmed without a benchmark.  Now last but not least, cellular connectivity! All the SoCs have 5G connectivity provided with them. It should be noted that the 5G network which has been considered so far are not completely 5G, rather they are 5G non-standalone (5G-NSA) network, that uses 4G LTE core network in an Integration with 5G new radio (NR) Radio Access Technology. This 5G will be covered in great detail in a future blog.

Conclusion:

So far, we have explored the different processors for mobile applications, more impression was given on smartphone processors. We came to know how exactly smartphone processors work with other hardware in an SoC environment. We have not considered a typical design of an ARM core which will be a great exercise to go and check on their website. I hope, next time when you will encounter a processor of a mobile device, you should have many things known about them. As far as the overall performance is concerned, the ‘benchmark test’ tells the real tale.