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Abstract—In today’s modern world, Internet has become a basic
need of everyone. Apart from the basic features of the Internet,
i.e., surfing and web browsing, we need additional features such
as entertainment, online video streaming and socializing etc. To
utilize different features of the Internet, different devices are
available that varies in terms of cost, computing power, display
and energy consumption. In this paper, we present how different
features of the Internet could be surfed by having a single device
Raspberry Pi. We compare different characteristics of Raspberry
Pi with modern computing devices like Smartphone, tablet PC,
laptop and smart TV. Our results show that essential computing
tasks could be achieved in more energy efficient way. We prove
that Raspberry Pi consumes less power and can save notable
amount of energy in routine computing tasks
INTRODUCTION
The Raspberry Pi is a credit-card size computer that was
developed in the Laboratory of University of Cambridge and
released by Raspberry Pi Foundation in 2012 [1].The aim of
Raspberry Pi was to stimulate the teaching of computer
science at school [2]. The Raspberry Pi has a 700MHZ
ARM11 co-processor [3], Broadcom Video Core IV[4]
graphics, 512 MB RAM on model B and 256 MB RAM on
model A. This microcomputer has 85.6 X 53.98 mm(3.37 X
2.125 in) size and its weight is 45g (1.6 oz.)[4], it has two
USB ports in model B and one in model A, 1 Ethernet port on
model B. It has GPIO (general purpose I\O) connectors so we
can communicate with sensors, motors and other embedded
systems [1]. It has open-source Linux (Raspbian) operating
system, you can also run Android, Arch Linux ARM, Firefox
operating system, Google chromium, Fedora, Plan 9 ,RISC
and UNIX[2] . Raspberry Pi has different usages like you can
use it for watching movies, playing games etc. Raspberry Pi
has a flexible platform for applying utilities and for
experimentation [5].
“The Pi Store” is the market to download its applications.
Raspberry Pi provides a graphical desktop environment so that
it can be used for general purpose reading e.g. reading
documents, working with spreadsheets. It can also be used for
web browsing as simply as in smartphones, tablets, laptops,
desktops and Smart TVs. As these devices can perform many
similar tasks but energy consumption of these devices varies
for these specific tasks.
The rest of the paper is organized as follows. Section II
overviews the related work, Section III discusses the energy
efficient computing of different devices, Section IV provides
numerical results before the paper is concluded in Section V.
II. LITERATURE REVIEW
With the advancement of technology, different devices are
manufactured which are enriched with different features based
on user needs. Many features of these devices are common but
all are not similar, even same features are presented differently
by different devices. So it is important to discuss these modern
devices briefly
A. Smartphone
Smartphone is handheld device with functionalities of
several other devices such as computer, cellular phone, music
player, radio, GPS etc.[6]. They also support 2G/3G/4G data.
It is pocket or handbag size device and very easily portable
and light weight. It can be used for reading, Internet, gaming
messaging, mailing and many other purposes. Smartphones
are available with different operating systems such as android,
windows, blackberry, Symbian and I operating system. Energy
consumption of different model varies with respect to screen
size, operating system and available hardware. Whereas HTC
sensation XL having 4.7 inch screen needs 5 watt power to run
and costs 400US$ [7].
B. Tablet
Tablet is mobile computer with display, circuitry and
battery in a single unit. A tablet is easily portable and light
weight computing device when compared to a laptop. It has
virtual keyboard and have touch screen. Their screen sizes are
approximately 7 to 10.1 inch. Tablets are available with
android, windows, blackberry and I operating system. Tablet
normally gives more than 8 hours battery time. Energy
consumption is comparatively less than laptop. It just need
power of 25 watt to run[8]. It comes with some pre-installed
applications but they can be enhanced by downloading and
installing from relevant app store. Price of tablets varies with
respect to the performance and screen size, but they are
cheaper than laptops.
C. Laptop
It is a portable computer, small enough to fit on lap. It
provides opportunity to study, Internet usage and gaming and
even can do programming in many different languages.
Windows, mac, Linux and other operating systems can run on
it. It can be run on battery or AC power. It approximately runs
on 50 watt[9]. And its battery time is 2-4 hours. Now a days
ultra-books are available in markets which are very light
weight and give more than 8 hours battery time. Laptops are
available with different performances so their prices also
varies with performance.
D. Desktop
A computer designed to fit on the top of the desk. Easily
upgradeable, available with window, mac, Linux and few
other operating systems. Watching movies, Internet surfing,
studying, programming and many other uses. It is most
powerful among all these devices. So its energy consumption
is also high. It needs 82 watt energy to run without
display[10].
E. Smart TV
Smart TV is a TV with built-in Internet capabilities. It
provides access to stream videos and music. It comes with
different operating systems. It also provides access to social
networking apps. It has capabilities to check emails, web browsing, gaming, watching movies etc. A smart TV with 32
inch display needs approximately 80-110watt to run.
III. ENERGY AND PERFORMANCE EVALUATION
COMPARISION
In this section, performance evaluation of different
devices is discussed and energy efficient computing is
measured. Raspberry Pi can be boot-up with just a power of 5
Volts [11]. For normal usage Raspberry Pi run on just 2.25
watts without display and energy consumption is 8.1
kilojoules per hour (kJ/h), whereas laptop generally runs on 50
watts[9] and consume 180 kJ/h and desktop runs on 82 watts
without display[10] and energy consumption per hour is 295.2
kJ. So Raspberry Pi consumes 22% less power than a laptop. It
has vast range for display, it can be connected with TV, LCDs
and laptop’s or mobile screen as well. On the other hand
smartphone (HTC sensation XL) runs on 5 watt and consume
energy 18 kJ/h, tablet runs 25 watts [8] and consume 90 kJ/h
where as smart TV run on 221 watts and energy consumption
is 795.6 kJ/h.
Although these devices can be used for web or education
but people prefer those devices which yield more satisfaction
and fulfill their requirements, like they do not want to use web
all the time, they want entertainment too. Even continuously
studying is also difficult. While buying the device, cost also
plays an important role, people prefer to buy device with
maximum qualities and minimum cost. Users having
confidential data in these type of devices prefer security
instead of user-friendliness. Energy efficiency is also
important which affect power savings at national level.
Portability also plays important role. Desktop and Smart TV
are not portable at all so it will be difficult to carry them from
one place to another. Whereas laptops are comparatively more
portable but do not give good battery time as compare to
tablets, but their performance is better, and also provide
environment for programming. On the other hand smartphones
are very portable and can easily put into pocket and handbag.
The brief comparison is discussed in the Table 1. Table 1
shows the comparison of specific model of different devices.
Energy efficiency is calculated in kilojoule per hour.
According to the table Raspberry Pi is most energy efficient
device with just credit card size. Whereas desktop and Smart
TV are highly energy consuming devices with no portability.
Laptop although provides almost all the services without any
difference from desktop and is also portable and energy
efficient but more expensive than desktop. On the other hand
only smartphone is available with cellular services.