Comparing The Atom And Arm Mobile Processors Computer Science Essay

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In today's technological society, the main factor that manufacturers making smart phones take into account when choosing a processor is the performance that it gives and the amount of battery consumption that it uses.

The objective of my research was to compare the ARM processor against Intel's Atom and to make a recommendation as to which would be best suited to be used in a smart phone.

After researching the processors, I have concluded that an ARM processor would be the best choice for the project. The main reasons for this are as follows:

The ARM processor has a simpler instruction set than Intel's Atom

The power consumption of an Atom processor is on average 6 times greater than that of an ARM

An Arm processor gives faster web browsing performance (1)

The Arm processor chip is around 1/3 of the size of the Atom

Arm processors dominate the smart phone market, over 90%, and have proved to be a success (2)

ARM processors are designed primarily with smart phone use in mind

Arm also allow customers to customise the chips whereas Intel do not

The cost of an arm processor is much lower than that of an Atom due to the chip having many more capabilities


The ARM Architecture was originally developed for mobile processing applications in the early 1990's and was designed for high-performance and very low-power implementations. By having a RISC style architecture that gives high performance it enables instructions to be carried out quickly due to their simpler format. The simpler instruction set architecture means that they are suited for low power applications e.g. smart phones.

Arm has two main processors for smart phone use, the A8 and A9. These are used in over 90% of smart phones worldwide including Apples iPhone, HTC, Palm Pre and Samsung smart phones. It is clearly the smart phone market leader with over 90% of smart phones having some sort of Arm processor.

Arm allows their chips to be customised by the customer, therefore allowing components e.g. memory, video and screen controllers. This will cause the overall size of the device to be smaller as more components can fit on a chip rather than having to be separate. This also lowers the cost

The latest A9 can deliver clock speeds of up to 2GHz whilst still having low power consumption with an average power consumption of around 250 milliwatts.

The Apple iPhone 4 uses an arm cortex A8 processor that only takes up ¼ of Apples chip (A4), the rest of the processor is filled with power-saving logic cores, analogue circuits and video digital-to-analogue converters. The iPhone manages to run at 1GHz and still offers a good rate of power consumption.

Intel's Atom uses the Intel x86 set architecture. There are two atom processors available for smart phone use at the moment, the Atom z5 and z6. Intel have only recently started making processors for smart phones, the 1st being the LG GW990 in 2010 (3) and have proven that the android operating system can be run on it.

The Atom processors also have technology that incorporates a single chip, the Intel System Controller Hub that enables PC-like capabilities with integrated graphics and a wireless radio.

Atom is based on a micro-architecture designed for small devices with low power consumption. It is also compatible with the Intel Core 2 Duo instruction set, and supports multiple threads for better performance and increased system responsiveness. Intel claim that the power consumption on one of its chips used in a smart phone is low and that a smart phone built around the Atom chips would get either 10 days of standby power (25 milliwatts), 48 hours of audio playback(120 milliwatts), five hours of 720p video(1.1 watts), or six hours of 3G calls(1.1 watts). (4)

To enable it to have an efficient energy use on small devices, the atom has a smart cache, with a more efficient bus design, which enables more efficient data sharing, and a power optimized front side bus with macro-ops fusion for faster execution of instructions at lower power. All of these help keep power consumption to a minimum and maximising the capabilities of the processor

Comparing Atom and Arm

One of the major differences between Atom and Arm is that Atom can run Microsoft's Windows 7 operating system, Google's Android and MeeGo, whereas currently Microsoft don't support the ARM architecture however, in January 2011, it was announced that the next generation of Windows would support ARM processors (5)

Arm has also been making processors for mobile devices for 20 years whereas Intel has just entered the market, and therefore has less experience and knowledge on what these devices require in terms of specification, power consumption, and applications.

Another difference between the Atom and Arm processors is the power consumption. Although an atom processor may be able to run faster, if an arm processor was clocked at the same speed, it would typicality use a fraction of the power the atom uses.

A study found that webpage loading on an atom processor at double the MHz of an arm processor gives no performance improvement (6) thus causing the atom to use more energy to get the same end result.

Arm processors are also much cheaper as arm allow the customer to customise the chips, with things like a graphics accelerator, memory, camera interfaces whereas an Intel do not allow this and therefore more chips must be purchased to cope with this, therefore increasing the size, cost and power consumption of the device.

Finally, Atom can run PC games whilst arm cannot. If Intel can make a good processor for a smart phone whilst keeping power consumption at a minimum and can make PC quality mobile games/apps it could overtake ARM with the mobile gaming device market.

After taking all the above into account, it is clear that Arms A8 or A9 processors are clearly the best choice, as they are designed for smart phones, used widely across the mobile device market with great success, offer a good rate of power consumption and at the lowest cost. The A8 and A9 processors offer high performance, in particular for web browsing, which is what smart phones are used for a high percentage of the time, whilst keeping the restrictions on power consumption at a minimum therefore increasing the time the user can have between charges.

Works Cited







Part 2- System/OS Firmware Selection

Executive Summary

For consumers today, a main factor when purchasing a smart phone is the operating system that it has.

There are many operating systems for smart phones with the main ones being; Apples iOS, Symbian, and Google's Android.

The objective of my research was investigate and research the different operating systems that can be used on the device and to recommend which one that I think would be the best choice for the project.

After researching the processors, I have concluded that Google's Android Operating System is the best choice for the project. The main reasons for this are as follows:

Manufactures have rejected Symbian in favour of Android

Android was created with smart phones in mind

Android is freely available to licence and can be installed on most devices easily

Android is the market leader with the most widely support available

There are thousands of apps available

Apple iOS

Apples iOS operating system, written in C, C++ and objective C, is designed for its iPhone and iPad devices. The most recent version of iOS is 4.3. IOS has a 16% share of the smart phone market in 2010 due to its exclusivity for apple devices.

The latest version allows for multi tasking, GPS and has better power consumption

In iOS, there are four abstraction layers: the Core OS layer, the Core Services layer, the Media layer, and the Cocoa Touch layer. The operating system uses roughly 500 megabytes of the device's storage (1)

The cocoa touch framework focuses on touch-based interfaces and optimization and allows multi touch actions. It also has built in functionality for GPS and internet browsing.

IOS has built in power management, which helps with lowering power consumption. This conserves power by shutting down any hardware features that are not currently being used, thus giving more power to the hardware that requires it.

A drawback from iOS is that it cannot run adobe flash applications as it has no support for this, therefore the full internet cannot be viewed to extent.

Apple have an SDK for 3rd party developers to make applications for the device and run on iOS, however they must be approved by apple and bought via the App store. To do this the iOS development kit must be purchased from Apple.

The main drawback and major issue, is that apple do not sell or licence iOS therefore, it cannot be used on our system unless it is an Apple Device.

Symbian OS

Symbian is a Linux based, open source operating system maintained by Nokia. The latest version is Symbian^3 with version 4 expected later in 2011, and had a 43.5% share of the 2010 smart phone market (2).

The Symbian kernel supports fast real-time response to build a single-core phone around it-the real-time kernel has a microkernel architecture that contains only the minimum, most basic primitives and functionality. It contains a scheduler, memory management and device drivers, with networking, telephony and file system support services in the OS Services Layer or the Base Services Layer. (2)

The three main principals of the OS: the integrity and security of user data is paramount, user time must not be wasted, and all resources are scarce. To adhere to these, the OS is optimised for low-power battery-based devices like smart phones.

As Symbian programming is event-based, saving power consumption is achieved by switching the CPU into a low power mode when applications are not directly dealing with an event

The main features of the operating system layer are generic OS services, communications services, multimedia and graphics services and connectivity services.

Some examples of smart phones that use the Symbian OS are the Nokia N8 and Sony Ericsson Satio.


The android operating system, programmed in C, C++ and Java, is open source and owned and developed by Google. In late 2010 Android became the world's top selling smart phone OS with over 30% of the US market.

Android relies on developers to make applications and features for it, as most of the operating system code is available freely however, device manufacturers cannot use Google's Android trademark unless Google certifies that the device complies with their Compatibility Definition Document.

Android has all the same features as iOS and Symbian and uses the Linux Kernel for the OS. The Linux kernel runs on Linux version 2.6 for core system services such as security, memory management, process management, network stack, and driver model. The kernel also acts as an abstraction layer between the hardware and the rest of the software stack.

It then has a series of libraries that operate systems like the internet and media, and finally a layer for the application framework, which manage the resource and operation.

The main reason for Androids success is that it has Google backing it. A Google is a large, well-known and trusted brand, more people can relate to the name.

Some examples of smart phones that use the Android OS are the Samsung galaxy, Motorola Droid, Dell Streak.

Comparison between OS' (3)

The main difference between Symbian and Android is that a phone that has a version of the Symbian OS will always have that OS unlike Android, which releases new and updated versions of its OS, which can be downloaded when available.

Symbian has been around for a while, and existed when smart phones were not very common, designed to work on phones that have keypads. On the other hand, Android was designed from the very beginning to work with touch capable devices. This has caused Symbian touch screen devices to have more menus, which are harder to access as they were designed to be found via buttons, whereas on an android the most common menus can usually be found quickly from the home screen.

The power behind the Android OS is much greater than Symbian and has a much better user interface.

Android's of features includes an Application Framework that allows users to reuse components. With media support for video, images, audio, its multimedia performance is also very high. It also has features like an accelerometer, compass and GPS. However, Android does have a poor support for Web games, which makes it quite unusable for playing online. Whereas Symbian, on supports C++ programming and because of its Java support, it can support high quality games.

In conclusion, the operating system that I am going to recommend for the project is Google's Android.

The reasons for this are that it is the most widely supported operating system, the code is open source and issues are publically reported, with developers worldwide creating solutions to fix them. Android now has thousands of applications, which is what most consumers look for when buying a new smart phone.

In addition, recently Samsung and Sony Erricson have both rejected Symbian in favour of Android; therefore, as the number of handsets with a Symbian OS goes down, the support for it will also deteriorate.