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Current Hardware and PC Operating Systems

Guide to Operating Systems Second Edition

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Understanding CPUs

• The system architecture includes the number and type of CPUs in the computer, and the communication routes, called buses, between the CPUs and other hardware components, such as memory and disk storage

• The CPU is the chip that performs the actual computational and logic work

• Most modern PCs have one such chip, and are referred to as single-processor computers

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Understanding CPUs

• There are also computers that have multiple CPUs; many have two, some have as many as 64 or more

• These computers are generally referred to as multiprocessor computers

• CPUs can be classified by several hardware elements, the most important of which are:– Design type – Speed

– Cache – FSB Speed

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Design Type

• Two general CPU designs are used in today’s computers: CISC (Complex Instruction Set Computer) and RISC (Reduced Instruction Set Computer)

• The main difference between the two is the number of different instructions the chip can process

• The instruction set, or the list of commands the CPU can understand and carry out, can get quite complex

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Design Type

• A processor that works like this is called a Complex Instruction Set Computer (CISC) CPU

• The CISC CPU offers advantages and disadvantages

• A big advantage is that you need only general-purpose hardware to carry out commands

• Major disadvantages to the CISC design include the complexity of hardware needed to perform many functions, and the complexity of on-chip software needed to make the hardware do the right thing

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Design Type

• An even bigger disadvantage is, ironically, the need to continually reprogram the on-chip hardware

• The complex operations that a CISC CPU carries out slow it down because all sorts of hardware on the chip must be set up to perform specific functions

• The RISC CPU design, on the other hand, requires very little setup for specific tasks because it has hardware on the chip that is specially designed and optimized to perform particular functions

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Design Type

• RISC CPUs typically use a technique called pipelining, which allows the processor to operate on one instruction at the same time it is fetching one or more subsequent instructions from the operating system or application

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CISC versus RISC Processing

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Speed

• There are many ways to indicate speed, but the most obvious indicator is the internal clock speed of the CPU

• The clock provides this schedule to make sure that all the chips know what to expect at what time

• The internal clock speed tells you how many clock pulses, or ticks, are available per second

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Speed

• In addition to performing fast operations inside the CPU, the chips also must be able to communicate with the other chips in the computer

• This is where the external clock speed of the CPU comes in

• While a CPU may run internally at a speed of 1.5 GHz, it typically uses a lower clock speed to communicate with the rest of the computer

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Cache

• Most modern CPUs have cache memory built into the chip

• This memory is extremely fast—it typically runs at the same speed as the processor—and therefore is expensive

• If the processor needs a number stored in the cache memory on the CPU, it probably won’t have to wait to obtain that number

• This memory is referred to as Level 1 (L1) cache

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Cache

• Some CPUs have one or two more levels of cache memory, which are typically on a separate chip

• This is called Level 2 (L2) cache, and it normally runs at the same speed as the external CPU clock

• When both L1 and L2 cache are built into the processor chip, the cache on a separate chip is called Level 3 cache

• There is a specialized piece of hardware called the cache controller that predicts what data will be needed, and makes that data available in cache before it is needed

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Front Side Bus

• In essence, the bus is a pathway over which data travels between various internal system components. The front-side bus (FSB) is the segment of the system bus that carries data between RAM and the CPU; it generally has the greatest effect on overall benchmark performance. A system with high-performance processors and other components should also have a fast front-side bus. The lower cost Athlon XP, for example, is paired with a 266MHz or 333MHz FSB, while the faster Pentium 4 uses either a 400MHz or 533MHz system bus. In practice, the FSB will be an issue with only hard-core applications, such as digital video.

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Popular PC Processors

• These CPUs are:– Intel PIII & P4

– Intel Itanium

– AMD

– Motorola

– SPARC

– Alpha

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Intel

• The most popular CPUs in use in PCs today are designed by Intel, and typically found in what are often called IBM-compatible PCs. The first player in this line of processors was the 8088, the CPU found in the original IBM PC

• Processors were functionally the same untill Intel released something called the Multimedia Extension (MMX)

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Intel

• These chips are nearly identical to a regular Pentium, but they have a few new instructions to deal with multimedia—for example graphics and video—and the chip design is optimized for handling large amounts of data

• Another innovation with the Pentium 4 is the presence of two math coprocessing units, called arithmetic logic units (ALUs), for handling math-related calculations

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Intel CPUs

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Intel Itanium

• The Intel Itanium processor is a significant departure from previous Intel processors in two aspects: it is built on the RISC-based EPIC architecture and it is a 64-bit chip

• These differences alone are enough to make this a very fast processor

• The Intel Itanium processor is intended for very large-scale operations that match powerful mainframes

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AMD

• Advanced Micro Devices, Inc. (AMD) is a manufacturer of Microsoft Windows-compatible processor chips and non-volatile (flash) memory, which compete with Intel products in the processor market

• AMD CPU chips include the Athlon and the Athlon XP

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AMD

• Athlon XP is the Price/Performance Leader in the PC based CPU Market

• AMD and Intel go head to head on benchmarks with each company winning from time to time

• However, AMD has a lower price point and therefore consistently wins when considering value, price and performance

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Motorola

• Motorola is the next most popular CPU maker, and its chips are typically found in Macintosh computers

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SPARC

• It is useful to briefly mention a few other RISC processors, one of which is the SPARC processor designed by Sun Microsystems

• SPARC CPUs have gone through many incarnations, and the RISC processor is the most popular on the market today

• The UltraSPARC III is the current version of the SPARC processor at this writing

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2O/S ComponentsActiveX and the

Component Object Model (COM)• Much of the easy manipulation of the user

interface in Windows 95 and beyond is made possible by a new technology called ActiveX

• ActiveX, along with its parent, the Component Object Model (COM), is a standardized way for objects, such as programs, files, computers, printers, control panels, windows, and icons, to communicate with each other

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ActiveX and the Component Object Model (COM)

• Objects (such as folders, icons, menus, and almost any other object you see on the desktop) consist of a series of properties

• The COM and ActiveX technologies enable an object to “sense” when it is interacting with other objects, such as the mouse printer, the desktop, the trash can, or the Start menu

• The COM and ActiveX technologies allow you to simply drag files from one place to another

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ActiveX and the Component Object Model (COM)

• ActiveX and COM also allow shortcuts (see the arrow in Figure 2-4), small ActiveX objects, on the desktop

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The Registry

• The Registry is a database that stores information about hardware and software configurations, and all sorts of other data needed to make the operating system and applications run

• In Windows 95 and later, the Registry is the only correct way to store configuration information, as well as much of the general information that is shared by multiple parts of the operating system or application programs to make COM and ActiveX work

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The Registry

• The Registry is a hierarchical database that provides the following information:– Operating system configuration– Service and device driver information and configuration– Static tuning parameters– Software and application parameters– Hardware configuration– Performance information– Desktop configuration

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Windows 98

• Windows 98 is similar to Windows 95 in many ways

• It runs on similar computers, and it provides roughly the same capabilities

• Many of the problems experienced with Windows 95 are solved in Windows 98, particularly Registry problems

• Windows 98 includes Registry checks and automatic Registry repair when the computer is booted

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Windows 98

• Windows 98 is written as a 32-bit application, much like Windows 95

• PnP support is greatly expanded, and advanced power management features are now included in the operating system

• This is especially important for users of battery-operated laptop computers

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Windows 98

• Windows 98 is also updated to support many new hardware standards, such as Universal Serial Bus (USB), a relatively high-speed input/output port, and updated standards for multimedia, data storage, and networking

• Windows 98 uses improved cooperative multitasking for 16-bit applications and preemptive multitasking for 32-bit applications

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Windows 98

• The ActiveX technology was deployed as a standard feature in Windows 98, together with Internet integration and network functionality

• Windows 98 can be updated over the Internet

• Setting up dial-up connections and configuring the computer to use the Internet are simpler, plus there is support for high-speed networking

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Windows NT

• Development of Windows NT began as early as 1988

• Windows NT 3.1 was released in 1993 and version 3.5 was released in 1994

• Windows NT was initially an extension to IBM’s high-end operating system, OS/2, and was intended to support the emerging client/server networking environment

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Windows NT

• As client/server applications gained popularity, Windows NT development and the successive operating systems in the NT line, Windows 2000, Windows XP, and Windows .NET Server have experienced wide reception

• Windows NT, as is true of most operating systems, has gone through many iterations

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Windows NT

• Windows NT 4.0 looks and feels a lot like Windows 95 or Windows 98

• Many of the GUI elements are the same, such as the desktop, Windows Explorer, and the taskbar with the Start menu, as shown in Figure 2-6

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Preemptive Multitasking

• Windows NT uses preemptive multitasking rather than cooperative multitasking

• The advantage of preemptive multitasking is that the operating system is tightly in control of what the system will do at what time, which results in a much more predictable performance

• Besides preemptive multitasking Windows NT 4.0 employs multithreading, which is the ability to run two or more program code blocks as threads, at the same time

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Preemptive Multitasking

• Windows NT Workstation can use up to two CPUs and Windows NT Server can use up to four

• The system architecture that is used to perform this form of multiprocessing under Windows NT 4.0 consists of a set of CPUs that has access to the main memory of the computer

• All the CPUs can carry out actions at the same time

• This is known as symmetric multiprocessing (SMP)

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NT Server and NT Workstation

• Windows NT is offered in two versions: Windows NT Workstation and Windows NT Server

• Windows NT Workstation is the operating system for a person who needs a high-end, stable, and secure graphical operating system

• Windows NT Server is designed as a multi-user, server operating system for access over a network

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NT Server and NT Workstation

• In Windows NT Workstation, the kernel is optimized for maximum performance when used to run interactive applications, such as screen updates and fast retrieval and storage of data in memory and on disk

• In the NT Server edition, the kernel is optimized to provide maximum network and disk performance

• The Registry, mentioned earlier in the Windows 95/98 sections, plays an equally important role in Windows NT

• It is used as the central repository for configuration, hardware, software, and user information

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Networking Support

• Windows NT is designed as a multi-user system

• Windows NT supports network connectivity protocols that are compatible with IBM mainframes, UNIX computers, Macintosh computers, all Windows-based computers, Novell NetWare servers, and others

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Security

• A C2 rating means that the Windows NT Server network operating system provides security at many levels, as follows:– File and folder protection– User accounts and passwords– File, folder, and account auditing– File server access protection on a network– File server management controls

• The domain is an integral part of the Windows NT security model

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Security

• In every domain there is one primary domain controller (PDC)

• The PDC computer is responsible for keeping all usernames and passwords for all users who may want to contact the domain

A domain is a group of computers that share a common security database

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Windows 2000

• Microsoft Windows 2000 is a more robust operating system than Windows 95, 98, or NT

• This operating system represented a significant rewrite of the Windows NT kernel, and it was released in the year 2000, Microsoft chose to name it Windows 2000

• One advantage of rewriting the kernel is that Windows 2000 runs about 30% faster than Windows NT

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Windows 2000

• Windows 2000 has more advanced networking support than Windows NT because it supports new networking technologies, such as Virtual Private Networks (VPNs)

• A VPN is a private network that is like a tunnel through a larger network that is restricted only to designated member clients

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Windows 2000 Server and Windows 2000 Professional

• Windows 2000 Server and Windows 2000 Professional can be used on a server-based network to achieve a lower total cost of ownership (TCO)

• The TCO is the total cost of owning a network, including hardware, software, training, maintenance, and user support costs

• Windows 2000 Server is intended to play a key management role on the network by administering Active Directory—a database of computers, users, groups, shared printers, folders, and other network resources—and a multitude of network services

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Windows 2000 Server and Windows 2000 Professional

• Windows 2000 Server supports up to four processors, while Windows 2000 Professional supports up to two

• Windows 2000 Server also offers more services and user connectivity options that are appropriate for a server instead of a workstation

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Windows 2000 Server

• These services include the following:– The capability to handle virtually unlimited numbers of

users simultaneously

– Active Directory management

– Network management

– Web-based management services

– Network-wide security management

– Network storage management

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2Windows 2000 Server,

Advanced Server, and Datacenter Server

• Windows 2000 Server is divided into three different products to match the network application: Windows 2000 Server, Windows 2000 Advanced Server, and Windows 2000 Datacenter Server

• Windows 2000 Server provides a comprehensive set of server and Web services for up to four processor systems, and supports up to 4 GB of RAM

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2Windows 2000 Server,

Advanced Server, and Datacenter Server

• Windows 2000 Advanced Server is intended for high-end enterprise networks that require up to eight processor servers, clustered servers, or both

• Clustering is a technique in which two or more servers are linked to equally share the server processor load, server storage, and other server resources

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Server Clustering

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Windows XP and .NET Server

• Windows 2000 has evolved into two products, both containing the core elements of the Windows 2000 kernel: Windows XP and Windows .NET Server

• Windows XP is the desktop version of the new operating system, while Windows .NET Server is the server version

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Windows XP Desktop

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Windows XP and .NET Server

• Windows XP and Windows .NET Server offer more capabilities than Windows 2000 for keeping photo albums, playing music, running video and audio files, playing games, and using other multimedia applications

• Windows XP and Windows .NET Server also offer better Internet security through a built-in firewall and the ability to remotely control the computer over an Internet connection via a tool called Remote Desktop

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Windows XP

• Windows XP, comes in two versions: Windows XP Professional and Windows XP Home Edition

• Windows XP Professional is the upgrade to Windows 2000 Professional, and is intended for office and professional use

• This version of Windows XP has the ability to create accounts for different users who might use the operating system

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Windows 2000 Control Panel

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Windows XP Professional Control Panel

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Windows XP

• Programs written for Windows 95 and earlier operating systems may not run in Windows XP without using the new Program Compatibility Wizard

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Windows .NET Server

• Windows .NET Server comes in four versions at this writing, which are similar to the versions that are available for Windows 2000 Server: Standard Server (formerly Server), Enterprise Server (formerly Advanced Server), Datacenter Server, and Web Server (a new server version)

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UNIX

• All versions of UNIX that ship today adhere to one of the two main design standards, the Berkeley Software Distribution (BSD) standard or the System V Release 4 (SVR 4) standard

• Linux is a version of UNIX that is available free of charge, but some enhanced versions of Linux must be purchased

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UNIX

• Because UNIX comes in such a wide variety of implementations, it runs on almost any hardware platform; there are UNIX versions available for all platforms mentioned up to this point

• UNIX is a multitasking, multi-user operating system

• After startup, UNIX typically presents you with a request for a login, or username, followed by a request for a password

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UNIX Versions

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UNIX

• Just like other multi-user O/Ss the username and password you provide determine what privileges you will be granted on the system

• When your identity has been verified, you are presented with a UNIX shell or a GUI

• X Windows is one of the most popular GUIs

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UNIX

• X Window is similar to other windowed systems, and makes it easier to use a multitasking, multi-user operating system such as UNIX

• Red Hat Linux, for example, offers an X Window type GUI interface called GNOME, which can be installed or omitted

• All networking functions in UNIX are based on the BSD networking model, which provides support for TCP/IP (Transmission Control Protocol/Internet Protocol)

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Linux GUI Desktop

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Linux Terminal Emulation Window

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UNIX

• TCP/IP is the standard protocol in use on the Internet, and as such, UNIX computers are uniquely qualified to provide numerous Internet services

• In Linux, additional standard services include the Network File System (NFS), and support for other network systems such as those used by Microsoft, Apple, and Novell

• UNIX is also compatible with many popular databases, such as Oracle and Informix

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Mac OS

• The Mac OS was truly the first operating system to have an all-graphical user interface and an all-graphical shell

• The hardware architecture of the Mac OS is substantially different from the architecture used on most other platforms, especially because many of the graphical functions are included in the BIOS or firmware

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Mac OS X Desktop

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Mac OS

• This shell allows you to perform many operations with the mouse: starting programs, looking at the contents of directories, removing files, creating and removing folders ( a folder is the Mac equivalent of a directory, a usage later adopted by most other graphical operating systems), and so on

• Versions of Mac OS prior to 8.0 were not multitasking ; they were essentially task switching

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Mac OS

• The network functions in Mac OS are fairly evolved

• Peer-to-peer networking has been a standard feature of the Mac OS since its inception

• The protocol used is called AppleTalk, which originated in the Macintosh world

• OS X Incorporates TCP/IP

• Mac OS was always meant to be a desktop operating system, and there are no extended security features to keep users from getting access to files on the local computers

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Mac OS

• For networking, Mac OS allows the user to generate user profiles

• Throughout its history, the Mac OS has been known for its support of graphics, video, and sound capabilities

• Mac OS 9.x introduces features for better hardware and Internet access

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Mac OS X

• Mac OS X, where X means Version 10, is a significant update of the Mac OS

• OS X is based on a UNIX kernel and has advanced server and client networking features, supports TCP/IP, greater security and flexibility than previous versions of the O/S