# 4.3: Capacity of Devices

• Anonymous
• LibreTexts

$$\newcommand{\vecs}[1]{\overset { \scriptstyle \rightharpoonup} {\mathbf{#1}} }$$

$$\newcommand{\vecd}[1]{\overset{-\!-\!\rightharpoonup}{\vphantom{a}\smash {#1}}}$$

$$\newcommand{\id}{\mathrm{id}}$$ $$\newcommand{\Span}{\mathrm{span}}$$

( \newcommand{\kernel}{\mathrm{null}\,}\) $$\newcommand{\range}{\mathrm{range}\,}$$

$$\newcommand{\RealPart}{\mathrm{Re}}$$ $$\newcommand{\ImaginaryPart}{\mathrm{Im}}$$

$$\newcommand{\Argument}{\mathrm{Arg}}$$ $$\newcommand{\norm}[1]{\| #1 \|}$$

$$\newcommand{\inner}[2]{\langle #1, #2 \rangle}$$

$$\newcommand{\Span}{\mathrm{span}}$$

$$\newcommand{\id}{\mathrm{id}}$$

$$\newcommand{\Span}{\mathrm{span}}$$

$$\newcommand{\kernel}{\mathrm{null}\,}$$

$$\newcommand{\range}{\mathrm{range}\,}$$

$$\newcommand{\RealPart}{\mathrm{Re}}$$

$$\newcommand{\ImaginaryPart}{\mathrm{Im}}$$

$$\newcommand{\Argument}{\mathrm{Arg}}$$

$$\newcommand{\norm}[1]{\| #1 \|}$$

$$\newcommand{\inner}[2]{\langle #1, #2 \rangle}$$

$$\newcommand{\Span}{\mathrm{span}}$$ $$\newcommand{\AA}{\unicode[.8,0]{x212B}}$$

$$\newcommand{\vectorA}[1]{\vec{#1}} % arrow$$

$$\newcommand{\vectorAt}[1]{\vec{\text{#1}}} % arrow$$

$$\newcommand{\vectorB}[1]{\overset { \scriptstyle \rightharpoonup} {\mathbf{#1}} }$$

$$\newcommand{\vectorC}[1]{\textbf{#1}}$$

$$\newcommand{\vectorD}[1]{\overrightarrow{#1}}$$

$$\newcommand{\vectorDt}[1]{\overrightarrow{\text{#1}}}$$

$$\newcommand{\vectE}[1]{\overset{-\!-\!\rightharpoonup}{\vphantom{a}\smash{\mathbf {#1}}}}$$

$$\newcommand{\vecs}[1]{\overset { \scriptstyle \rightharpoonup} {\mathbf{#1}} }$$

$$\newcommand{\vecd}[1]{\overset{-\!-\!\rightharpoonup}{\vphantom{a}\smash {#1}}}$$

$$\newcommand{\avec}{\mathbf a}$$ $$\newcommand{\bvec}{\mathbf b}$$ $$\newcommand{\cvec}{\mathbf c}$$ $$\newcommand{\dvec}{\mathbf d}$$ $$\newcommand{\dtil}{\widetilde{\mathbf d}}$$ $$\newcommand{\evec}{\mathbf e}$$ $$\newcommand{\fvec}{\mathbf f}$$ $$\newcommand{\nvec}{\mathbf n}$$ $$\newcommand{\pvec}{\mathbf p}$$ $$\newcommand{\qvec}{\mathbf q}$$ $$\newcommand{\svec}{\mathbf s}$$ $$\newcommand{\tvec}{\mathbf t}$$ $$\newcommand{\uvec}{\mathbf u}$$ $$\newcommand{\vvec}{\mathbf v}$$ $$\newcommand{\wvec}{\mathbf w}$$ $$\newcommand{\xvec}{\mathbf x}$$ $$\newcommand{\yvec}{\mathbf y}$$ $$\newcommand{\zvec}{\mathbf z}$$ $$\newcommand{\rvec}{\mathbf r}$$ $$\newcommand{\mvec}{\mathbf m}$$ $$\newcommand{\zerovec}{\mathbf 0}$$ $$\newcommand{\onevec}{\mathbf 1}$$ $$\newcommand{\real}{\mathbb R}$$ $$\newcommand{\twovec}[2]{\left[\begin{array}{r}#1 \\ #2 \end{array}\right]}$$ $$\newcommand{\ctwovec}[2]{\left[\begin{array}{c}#1 \\ #2 \end{array}\right]}$$ $$\newcommand{\threevec}[3]{\left[\begin{array}{r}#1 \\ #2 \\ #3 \end{array}\right]}$$ $$\newcommand{\cthreevec}[3]{\left[\begin{array}{c}#1 \\ #2 \\ #3 \end{array}\right]}$$ $$\newcommand{\fourvec}[4]{\left[\begin{array}{r}#1 \\ #2 \\ #3 \\ #4 \end{array}\right]}$$ $$\newcommand{\cfourvec}[4]{\left[\begin{array}{c}#1 \\ #2 \\ #3 \\ #4 \end{array}\right]}$$ $$\newcommand{\fivevec}[5]{\left[\begin{array}{r}#1 \\ #2 \\ #3 \\ #4 \\ #5 \\ \end{array}\right]}$$ $$\newcommand{\cfivevec}[5]{\left[\begin{array}{c}#1 \\ #2 \\ #3 \\ #4 \\ #5 \\ \end{array}\right]}$$ $$\newcommand{\mattwo}[4]{\left[\begin{array}{rr}#1 \amp #2 \\ #3 \amp #4 \\ \end{array}\right]}$$ $$\newcommand{\laspan}[1]{\text{Span}\{#1\}}$$ $$\newcommand{\bcal}{\cal B}$$ $$\newcommand{\ccal}{\cal C}$$ $$\newcommand{\scal}{\cal S}$$ $$\newcommand{\wcal}{\cal W}$$ $$\newcommand{\ecal}{\cal E}$$ $$\newcommand{\coords}[2]{\left\{#1\right\}_{#2}}$$ $$\newcommand{\gray}[1]{\color{gray}{#1}}$$ $$\newcommand{\lgray}[1]{\color{lightgray}{#1}}$$ $$\newcommand{\rank}{\operatorname{rank}}$$ $$\newcommand{\row}{\text{Row}}$$ $$\newcommand{\col}{\text{Col}}$$ $$\renewcommand{\row}{\text{Row}}$$ $$\newcommand{\nul}{\text{Nul}}$$ $$\newcommand{\var}{\text{Var}}$$ $$\newcommand{\corr}{\text{corr}}$$ $$\newcommand{\len}[1]{\left|#1\right|}$$ $$\newcommand{\bbar}{\overline{\bvec}}$$ $$\newcommand{\bhat}{\widehat{\bvec}}$$ $$\newcommand{\bperp}{\bvec^\perp}$$ $$\newcommand{\xhat}{\widehat{\xvec}}$$ $$\newcommand{\vhat}{\widehat{\vvec}}$$ $$\newcommand{\uhat}{\widehat{\uvec}}$$ $$\newcommand{\what}{\widehat{\wvec}}$$ $$\newcommand{\Sighat}{\widehat{\Sigma}}$$ $$\newcommand{\lt}{<}$$ $$\newcommand{\gt}{>}$$ $$\newcommand{\amp}{&}$$ $$\definecolor{fillinmathshade}{gray}{0.9}$$

Teaching and learning requires students access and consume information, analyze and manipulate it, and create and disseminate it. Some educationally relevant information tasks, such as consuming text-based web sites (e.g. Wikipedia) and composing text (e.g. writing research papers) require little computing capacity. The rate of data creation is a small, so the necessary processing power is minimal, and the output is simple enough that a low- resolution display, and minimal network connection allows the work to be completed with no impediments caused by the technology. Other information tasks central to the curriculum, such as consuming or creating video require much greater computing capacity as the amount of data necessary to encode video is far greater than transferred for text. A device that is sufficient for a text- based activity may be insufficient for a video-based activity.

The capacity of a computer determines the nature of the information tasks that can be accomplished with it. Systems with greater capacity can process more data in a shorter time so users can use more sophisticated data sources and create more sophisticated data products using systems. When one attempts to use a computer with insufficient capacity, the computer is likely to “freeze” as it becomes unresponsive and many software features stop working. When a computer freezes repeatedly during a task, it lacks the capacity to perform the task.

Capacity is determined by several factors. In general, these factors determine the rate at which a system can access, process, and display information. Devices must be evaluated relative to a particular need, and IT managers will determine the capacity of the systems by evaluating:

• The speed at which the computer can process information- Processing speed is measured in giga-hertz (GHz); a processor operating at a speed of 3 GHz can perform 3,000,000,000 operations in one second. For the first generation of IT managers in schools, the processing speed of the computers was important as it determined the performance of the machines. For most of the 21st century, IT managers have been more concerned with the number of processors installed in parallel on the systems they purchase. The increasing processing capacity of computers has been referred to as Moore’s Law, and it has continued unabated for more than 50 years.
• The amount of random access memory (RAM) available to the processor- RAM has always been important in determining the capacity of a computer. It is relatively cheap and easy to increase, so RAM upgrades are a common method of increasing the capacity of computers. For some devices and for some purposes, however, increasing the RAM will have little effect on the perceived performance of the system. For example, if a student is using a computer that has 4 GB RAM installed to access G Suite and its performance is adequate, then doubling the RAM to 8 GB is unlikely to provide any better performance.
• The efficiency of the operating system- The OS manages memory and other system resources, and the rate at which it performs these tasks affects users’ perception of the computer’s performance. Over time, updates and changes to the operating system can decrease its efficiency and computer systems on which excessive applications or extensions to the operating system or web browsers can also interfere with operating system efficiency.
• The sophistication of the applications- Applications are the software used to manage and create information; many appicatons are sold in different versions. For example, schools can install and support various levels of video editing software. IT users can select from simple video editing software (sometimes packaged with the operating system) up to the same software used by professional video editors. Professional level software provides very sophisticated functions, but it requires hardware be upgraded frequently and it requires time and effort to use at its fullest capacity.
• The data rate at which the system can send and receive information on networks- This factor is increasingly a determinate of sufficiency. For many users, the capacity of computing devices is less about information processing and more about interaction enabling. Access to networks also expands the information capacity of our devices.; we update our software through the network and we move photographs from our devices onto network storage systems to free memory for more images (for example).

These variable aspects of computing systems that determine its capacity cannot be considered in isolation, as each contributes to the others. Consider the smartphones that many of teachers and students carry into school in their pockets. These are the latest in a series of “pocket-sized” technologies that have been evolving for decades and these have evolved together with networks. The processing speed and memory in pocket-sized devices exceeds that available in desktop computers manufactured only a few years ago, they connect to networks that make multimedia content available, and they allow users to create and share multimedia content with little effort. These devices have evolved through a combination of manufacturer push and consumer pull; as devices made more tasks possible, the demand for the products increased and motivated manufacturers to further improve and expand the devices they sold. Perhaps the best example of this effect is the co-evolution of the displays and the network capacity to access video. Better networks afforded users capacity to receives video and improved displays make the viewing experience acceptable which increased the demand for networks capable of delivering video to users of mobile devices. The reality of evaluating device capacity is even more complex than presented, as even more factors affect the capacity of some devices and the all of these factors continue to evolve. The battery technology necessary to power the devices in our pockets is one example. Improvements in batteries means they can to power devices longer than previous generations of batteries and they recharge more quickly. Network security is another. Engineers are developing more sophisticated methods of securing the networks we use and the data we store on them. Like other technologies, these methods are being refined through market pull and industry push but also through reaction to threats posed by the devices themselves and by misuse of the devices. The Internet of things (IoT) is the label given to the growing range of consumer devices that are connected to the Internet, and the IoT represents a vastly extended collection of source of input for computing systems, and it is possible because of increasing capacity of processors, expanding wireless networks, and decreasing size of circuits that has contributed to the mobility of technology.

Despite the evolution of a greater diversity of computing devices, which is likely to continue into the foreseeable future, schools are likely to be places where the original model of computing will continue to dominate technology-rich activity. Learning will find students accessing information, composing text, and creating media using general computing devices managed by the school and running software supported by the school. The fleets of devices managed by school IT professionals will be more diverse than the fleets managed by previous generations of IT managers. They will obtain, configure and install, manage and support computers with full operating systems, devices with mobile operating systems, and Internet-only notebooks.

## Systems with Full Operating Systems.

Of the devices marketed to schools, those with the greatest computing capacity will arrive with full operating system installed on the hard drive. Full operating systems include Windows, the Macintosh OS, and Linux (and open source operating system that can be used for free) which are installed on desktop and laptop computers. Of the devices on the market at any moment, these will have the most processing power (with both the fastest and the most parallel processors), the greatest RAM, and support the most sophisticated applications.

Full operating systems are available in multiple versions, and publishers will maintain the versions for several years; eventually operating systems reach the end of life when the publisher no longer releases security updates. In addition to the versions of the operating systems installed on user devices, there are versions of these operating systems available for servers as well as for mobile devices. Full operating systems are designed to connect to servers and, together, the OS on the users’ device and the network OS provide the most flexibility and most control of the software environment for IT professionals. They can be configured to use network resources, allow for multiple user profiles, and support network-based management. Obviously, the price of a unit will vary depending on the specifications, but IT managers who are asked about the cost of obtaining new machines that arrive with a full operating system are likely to estimate $1000 per unit. These devices tend to have the greatest longevity of all of the computing devices available in schools. It is not unusual to find desktop computers still operating and providing educationally relevant functionality more than five years after they were first purchased and installed. Laptop models tend to last less than five years, as they get damaged through rough use compared to desktop models. Decreasing performance of batteries and other components also limit the functional lifespan of laptop computers as well. Over the life of a computer with a full operating system, users will find it is characterized by decreasing performance as operating system and application updates require more system resources. IT managers accommodate for this by decreasing the number of applications installed, so it can continue to be used for tasks requiring the least capacity. The rationale for purchasing systems with full operating systems is typically grounded in the sophistication of the software that can be used on these devices. Students using a computer with a full operating system can use the same software that is used by professionals, so they can create sophisticated products. Further, they can use sophisticated output devices and peripherals. That software and those peripherals both add to the cost of the systems, but in many cases, that cost is necessary to provide the computing capacity necessary to meet the goals of the courses in which students are enrolled. Consider, for example, a high school in which theatre students write and produce one-act plays. Teachers may be interested in having students record the performance on multiple cameras, then use those recordings to create a single video version of the performance that incorporates different views. Editing and rendering such a video requires sophisticated video editing software that can be used only on a computer with a full operating system. In addition, the size of the files that must be managed to produce and render such a project require the processing power and the amounts of memory that are available only on a relatively expensive computer system with a full operating system installed. ## Mobile Operating System. The two mobile operating systems that dominate the consumer and education markets are Apple’s iOS (which is installed on iPads and iPhones) and Google’s Android (which is installed on a range of tablets and phones). Microsoft makes a version of Windows available for mobile devices and the open source community also makes version of Linux available, but these are much as less-widely used than iOS and Android. Mobile operating systems do allow users to adjust the settings and configurations, but these devices feature a single user profile on the device, so the changes that are made affect everyone who uses the device; this fact limits the usefulness of mobile devices in some schools. It is not unusual or IT professionals to find school leaders become strong advocates for purchasing mobile devices once they realize the ease of use that characterizes mobile devices. Those school leaders are not always fully aware of the difficulty of managing devices intended for single users in a school where devices are used by many different users for many different purposes. Among the populations that have found the greatest success using tablet computers that use mobile operating systems are those educators who work with special education students. A number of factors, including the mobility of the devices, the individualization that is possible with the apps installed on the devices, the multimedia nature of the devices, and the haptic control are all features that have been identified as useful for this particular population of students. Devices with mobile operating systems tend to be more affordable than those with full operating systems. Depending on the size of the screen and the quality of display and size of the memory, the same IT manager who estimated$1000 per unit for desktops or laptops would probably estimate $400 per unit that uses a mobile operating system, but he or she would be hesitant to make a final estimate before the option for managing the devices was specified. For example, some IT managers who purchase iPads decide to purchase a desktop computer and reserve it for the purpose of managing the devices through a third-party system. A further concern for deploying devices with mobile operating systems is the capacity of the wireless network. Mobile devices are designed to function the best when they are connected to the Internet. While users can take pictures, record video, create documents, and otherwise be productive on a mobile device with no network connection, there are limited options for adding software, sharing files, and otherwise using the devices when they are not connected to the Internet. ## Internet-only Operating Systems The newest type of device to enter the educational market is the Internet-only notebook. When these devices were first marketed, they had no functionality without the Internet, but later generations have added some offline functionality. Still, however, these devices are most useful in schools when they are connected to the Internet. The dominant device used in school that uses an Internet- only operating system is the Chromebook which is available from many manufacturers and in several configurations, but that all use the Google Chrome OS. With this device, one logs on to the device and the Internet simultaneously using a Google account. The only applications installed on the notebook is Google Chrome, which is the popular web browser. Productivity software (such as the word processor, spreadsheet, and presentation software) is provided through the user’s G Suite account; all other productivity tools that are used on the Chromebook must be available via a web service. There are limited options for using peripherals on a Chromebook, and printing is managed through Google’s Cloud Printing service. This service requires an administrator of the school’s Google Domain to configure a computer to be the print server, and it accepts and processes print jobs from any user assigned to the cloud printer. Managing a fleet of Chromebooks in a school finds an IT professional logging on to the online administrative dashboard provided by Google and selecting for the options available from Google or from third-party publishers; Google has a history of providing both G Suite and Chromebook management tools at no cost to schools, but many third-party services require a paid subscription. In addition to being limited by the options provided by Google and its partners, the decision to purchase Internet-only devices for students and teachers makes a functioning wireless network absolutely necessary in a school. Of the three types of devices marketed to school IT managers, Internet-only notebooks are the most affordable. The IT manager making a rough estimate of the cost would likely give$300 as a price per unit. That estimate would depend, of course, on the capacity of the wireless network in the school where to devices were to be deployed. The actually cost of deployed functional Internet- only devices may depend on upgrading network capacity.

This page titled 4.3: Capacity of Devices is shared under a CC BY-NC-SA license and was authored, remixed, and/or curated by Anonymous.

This page titled 4.3: Capacity of Devices is shared under a CC BY-NC-SA license and was authored, remixed, and/or curated by Gary Ackerman.