System On A Chip (SoC) For Smartphones

You may or may not have heard about the term System on a Chip (SoC) or “mobile processor” before. This term seems to be a new and strange concept to a lot of people, so if you do not know what it means, great.

If you don’t, you are welcome to the first part in a new series of posts. In these posts, I shall be breaking down the concept of the term System on a Chip (SoC). If you already what it is, do stick around and think of this as a refresher’s course.


Read: Top 100 Smartphone SOCs in the World 2022

System on a Chip (SoC)
Photo credits (@Vindainter, Pinterest)

Definition

According to Wikipedia, A system on a chip (SoC) or system on chip (SoC /ˌɛsˌoʊˈsiː/ es-oh-SEE or / sɒk/ sock) can be defined an integrated circuit (also known as a “chip”) that integrates all components of a computer or other electronic system.

These components typically (but not always) include a central processing unit (CPU), memory, input/output ports and secondary storage. All on a single substrate or microchip, the size of a coin. It may contain digital, analog, mixed-signal , and often radio frequency signal processing functions, depending on the application.

What this means is that all the vital components that work on your phone, that allow it to carry out it normal functions properly are all soldered onto one chip.

What is an SoC and what does it do?

What a System on a Chip (SoC) does

The apps and data on your phone need to be processed (processor cores, GPU and RAM), the music and files you have need somewhere to be saved for future use (ROM or flash memory), the photos taken by the camera need to be processed (Image Signal Processor), you need to be connected to the network and the internet so as to browse and receive calls (radio modem) etc.

All these components that permit these functions are soldered onto one chip. That chip then acts as the brain of your device, controlling and regulating all the functions of that device.

WHY IS THE KNOWLEDGE OF SoC IMPORTANT?

Every phone is powered by a battery and is run by an SoC. Every phone on the planet including the one you are using to read this post as we speak.

There are about 5 classifications of phones (entry-level, budget, midrange, flagship killers and flagships). The type of SoC you use determines which category your phone falls into. This is because SoCs are sold for different prices and they greatly influence the price and performance of your phone.

The SoC used in a device also tells how fast the phone would run, it’s processing power, how long it would stay relevant before becoming outdated and the type of features, apps and games it can access or process.

PARTS OF AN SoC

Processor cores (CPUs):

These are some of the most powerful components in any device. These carryout all the processing load of the smartphone.

Read: What is a GPU?

Graphics Processing Unit (GPU)

This is a powerful component that deals exclusively with pretty graphics. The GPU is responsible for handling a device’s visual output, particularly where the creation of three-dimensional images is concerned. It usually comes into play with video games and, more recently, augmented reality applications (where the device “augments” the feed coming from its camera with computer-drawn objects and effects).

RAM – Random Access Memory.

Works alongside the CPU and GPU to manage multiple tasks simultaneously. When you load an app, close it, and move to another app, the first app is stored in your device’s RAM. That means that when you return to it, content stays loaded so it can be accessed more quickly. Having more RAM is important for multitasking because it allows you to switch between apps, and have multiple operations going on at the same time even in the background.

ROM: 

Deals with internal memory storage size. Read-only memory is more commonly referred to as “storage” because it refers to the amount of space you have to store files and media on your device. If you put a song on your phone, download an app, or take a photo, this is where it goes.

Most phones today, come with at least 16GB of storage, though 32GB is becoming more common as users always need increasingly more space. Additionally, it’s important to note that you never are given quite the amount of ROM as you’re told, because a portion of it is occupied by the device’s operating system, as well as any subsequent updates. In other words, the amount of storage that you’re unable to use may grow through the life of your phone, which is why users frequently turn to another source for extra space.

Camera ISP (Image Signal Processor):

An integrated Image Signal Processor provides the platform for many of your smartphone’s camera functions. It is designed to deliver a tightly bound image processing package and enable an improved overall picture and video experience. An integrated ISP can also be invaluable when it comes to things like instant image capture, high-resolution support, image stabilization, and other image enhancements.

Audio and Video:

A good processor will also have dedicated processing units that handle audio and video. In a Snapdragon processor, a component called the Digital Signal Processor (DSP) handles music playback and other audio processing scenarios that the CPU would otherwise have to do. The same applies to video capture and playback, for which there is a dedicated video engine designated to handle these tasks. The concept of distributing work among these areas is what makes processing so fast and efficient in a Snapdragon powered device.

Radio (RF Transceiver) & Modem

This is the network adapter that is included in the SoC. The types are 2G, 3G/H+, 4G and 5G. The modem included on the SoC determines its range of network connectivity. These components control your connection to the world. Broadly speaking, the RF Transceiver receives and transmits voice connections and the modem enables your phone to send and receive digital signals.

Interface

These are connections that allow you to use your phone to interact with other appliances and electronics. They are USB, OTG, HDMI, MHL etc. Some devices also have an infrared (IR) blaster for controlling household appliances like TVs, ACs etc.

HOW DOES AN SoC WORK?

The components of a system on a chip (SoC) all work together to process commands into action and information into data. The CPU cores accepts and processes commands and information. The speed at which it does this is known as clock speed and is calculated in Gigahertz. CPU cores can be overclocked or under-clocked. The better the CPU, the faster it would perform its duty and process commands into data.

The RAM then caches (stores) this data so the CPU doesn’t have to spend time and resources doing it all over again. If the CPU is slow, the phone tends to lag. If the CPU is powerful but the RAM is full, the phone will also lag. The higher the processing speed, the better the CPU. A high RAM with a poor CPU will still produce a poor performance on heavy use.

While high clock speeds and a good number of RAM are important, they only tell half the story. They need the other parts of the SoC to function optimally. The clock speed measures, in gigahertz, the speed at which a CPU is able to process instructions. All things being equal, a 2.5GHz processor will be faster than a 2.0GHz processor. But things are rarely equal. A newer version of a processor is likely to be faster than an older one, even at slower speeds; a CPU based on a newer architecture is likely to be faster; and the number of cores also makes a difference.

A good CPU with a bad GPU is like a car with flat tyres. A smartphone is an audio-visual device hence it needs a good GPU to display graphics. A poor GPU will not only render poor displays or sometimes even refuse to display, it will slow down the processor.

Architecture

The architecture of the CPU also has a good influence on how well it will perform. The most commonly used is the ARM. A 64-bit system will perform better than a 32-bit system. Chips that include all of their components on a single substrate tend to do better than those that do not.

Build process

Build processes are also very important and with a system on a chip (SoC), smaller is better. A 7nm SoC will dust a 24nm SoC. Chips with bad build quality tends to suffer from heating problems, thermal throttle and lag. The following are examples of build processes (*smaller is better): 28nm, 24nm, 12nm, 11nm, 7nm etc.

Regularly, manufacturers are trying to produce better SoCs by producing smaller and better build qualities, faster clock speeds for CPUs, GPUs and RAM and trying to eliminate or reduce the amount of heat generated from the process.

SoC MANUFACTURERS

Qualcomm

is behind the Snapdragon series of SoCs, and they are arguably the most prominent SoCs used in recent years, being featured in most of the latest high-end devices. Qualcomm has broken up its products into four classes: 200 (entry level), 400 (budget), 600 (midrange), 700 (upper midrange/budget flagship) and 800 (flagship). In Qualcomm’s naming convention, the processors get faster as the numbers get bigger. So if you read that a phone contains a “Snapdragon 865,” you’re looking at Qualcomm’s top-of-the-line processor. Conversely, a “435” is a relatively lower-end chipset.

Apple

created their own Apple Ax series, with the latest being Apple A13 bionic.

Google

had the Google Tensor made for their Pixel line up. The Tensor is an AI/Machine Learning focused SoC.

Samsung

is behind the Exynos series of SoCs, which see most of their usage inside alternate versions of Samsung Galaxy phones, as well as Samsung’s Chromebooks.

Nvidia

is behind the “Tegra” series, which are gaming-focused SoCs taking advantage of similar technologies as Nvidia’s desktop GPUs. Nvidia uses these Tegra chips mostly in their own niche devices, but they sell to other manufacturers as well.

Intel

is behind the “Atom” series of processors which are x86 and used mostly in low-end laptops and tablets.

Huawei

are the owners of HiSilicon which makes Kirin chipsets which are used primarily for Huawei phones. The Kirin 990 is amongst some the best SoCs around.

Mediatek

is the second-largest producer of processors in Android phones. Devices running their chipsets are typically more common in Asia and Africa, though you can certainly find products in the Americas and Europe containing their hardware. MediaTek’s high-end processors are known as the Dimensity series, with the Helio G and P series slotting just underneath. The Helio A are for entry level devices. The rest of its offerings have less remarkable names, beginning with MT67**, followed by some more numbers. As you’d expect, the bigger the number, the more powerful the processor — so an MT6753 outclasses the MT6738, for example

Unisoc

chipsets services the very bottom end of the market for entry level smartphones. The chips are also called Spreadtrum.

This brings us to the end of the introductory post about Processors, there is more to come. Do not hesitate to hit me up in the comment section.

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