. © 1995-2004 Dave Krauss, Michigan State University Things to Consider Before Buying a Computer In the initial stages of determining what sort of computer you need to get, at some point you need to ask yourself, what am I going to be using the computer for? Whether you intend to write papers for class, surf the World Wide Web, or just play computer games, you need to have an idea of what the minimum requirements the computer needs to have. If all you intend to do is just write letters using a DOS based word processing program, a 386 or 486 system with a couple megabytes of memory is more than adequate. If you want to use a Windows version of some word processing program, then your requirements go up a bit, particularly on the amount of RAM memory and hard disk space. If you want to be able to surf the Web and play some of the multimedia on-line virtual reality games, then you need a higher-end system, with more memory, more disk space, and a modem or network card to connect to the Internet. Once you determine what you need the computer for, the next question that you need to ask yourself is how much money I can afford to spend. If you are looking for a Pentium 4 based system, expect to pay around $800 to $1000 for a good quality system including software and a monitor. You will no doubt see systems advertised for less than this, but there is a good reason why these systems are cheaper and we will discuss this a little later in this document. Buy as much PC as you can afford. Don't cut corners on the main system unit (monitor, processor, memory, disk space, etc.). If you are short on cash, hold off on the printer or a software application or two that you really don't need right away. Remember, this system is going to last you at least 3 or 4 years or more and you don't want to start running out of disk space or memory in the first week that you have it because you trimmed down the amount of memory or got a smaller hard drive so that you could afford to buy 18 different versions of a screen saver program!  Remember, you get what you pay for. If the price is cheap, most likely the components are cheap. For example, a good brand name 40 GB (Gigabyte) hard drive currently sells for $80 to $100. If a salesman talks you into their in-house brand for $20, make sure you have them throw in an extra set of rubber bands! Or a good quality 17 inch color SVGA monitor will typically go for somewhere in the range of $300 to $600. If the local computer store is selling a high-end model SVGA monitor for only $150, check to see if there is a crank on the side! If the PC of your dreams comes with Microsoft software, such as Office 2003, here is something you need to consider. Software that is purchased with a new computer has a special OEM (Original Equipment Manufacturers) license. That OEM license is tied to that specific PC and can not be transferred (uninstalled/reinstalled) on another computer. So, if you replace your new PC in a couple years, you will also need to purchase all of the OEM licensed software. OEM licensed software can only be installed on the original computer the software was purchased with. If you replace your computer every 3-4 years as I do, you may want to consider purchasing a retail copy of the software rather than buying the software with the new computer. The retail software is available either on-line or from your local computer store. With a retail copy of the software, if you ever replace your computer, you can uninstall the software from the old computer and reinstall the retail licensed software on a new computer. Depending on the application, retail software is going to cost you about 50% more than the OEM software purchased with the computer, but it will save you money in the long run. Finally, give yourself some room to work. Shoot for a dollar amount but be willing to spend a couple hundred more to get exactly what you want and something that you'll be happy with. If you say I want the best computer graphics workstation made, but I don't want to spend more than $200, I say go buy yourself a 64-pack of Crayolas with some colored paper, because that's all you can afford. Be realistic! What is the Main Purpose of the Computer If you have made the decision to buy a computer, there must be a reason or need that you have to get one, other than I have $1200 burning a hole in my pocket and I need to get rid of it! A good reason for buying a computer would be something like writing papers for a class or keeping track of your finances or business. A bad reason for buying a computer would be something like your best friend has one or everyone else you know has one, because you're probably never going to use it and you end up with a $1200 paper weight. Computer Terminology Before we get into our discussion of computers and components, there are a few terms that I should define first for those that are shopping for a computer for the first time: bits, bytes, megahertz, and gigahertz. These are the most common terms that are used to describe a computer's ability to store information and the speed in which it can process data. Bits & Bytes Defined Computers only work with binary numbers. A binary number, or bit for short, is the smallest unit of information that is used by a computer and consists of one of two different characters, a 0 (zero) or a 1 (one). A 0 would refer to off or false or no, while a 1 would refer to on or true or yes. A simplified example of the use of a bit would be when the computer is booted up, it sends out a signal to the printer connected to the computer to see if it is ready to accept documents. Assuming that the printer is turned on and isn't ready yet, it would respond by sending back a 0 indicating no, I'm not ready. If the printer is ready, it would respond by sending back a 1 indicating yes, I am ready. When you see the speed rating of a communications device, such as a serial port or a modem, the speed will be listed in bps or bits per second. A modem that has a rating of 56K bps (since K refers to thousand, that is 56,000 bps) would have the capability to sending or receiving 56,000 0s and/or 1s in one second. Since sending out information 1 bit at a time can be rather time consuming for the computer, information is sent as a package of data or instructions called a byte. A byte is made up of 8 bits of information, such as 00000000 or 10101010. Most of a computer's specifications are represented in terms of bytes, such as the computer's memory capacity or the size of a disk drive. The following table lists the various terms and their associated values:
Gigahertz Defined The speed of a computer depends on the amount of data its processor can manipulate in a given period of time and the processor's clock speed. The clock speed of a processor is measured by the number of electronic pulses it can produce in a second. Clock speed is built into the processor and is measured in gigahertz (GHz). Since giga means billion and hertz means times (cycles) per second, 1.0 GHz is 1 billion times per second. The speed of older, slower processors was measured in megahertz (MHz). Since mega means million, 500 MHz is 500 million times per second. The electronic pulses affect the speed with which program instructions are executed because instructions are executed at predetermined intervals, which are timed by the electronic pulses. For example, if we had a computer than contained a processor that was running at 1 GHz and it executed an instruction every 100 pulses, it would process 10,000,000 instructions per second (1 billion divided by 100). If the computer had a 500 MHz processor and executed an instruction every 100 pulses, it would process 5,000,000 instructions per second (500 million divided by 100). The amount of data that the processor can handle is called the word size and refers to the number of bits of information that can be processed at a time. An Intel Pentium processor can handle 64-bit words or 64 bits (0s and 1s) of information at a time. The older 486 computers contained 32-bit processors and could only handle 32 bits of information at a time. Before you jump to conclusions, a 64-bit processor is not necessarily twice as fast as a 32-bit processor. The 64-bit processor may be more than twice as fast in performing some tasks, but less than twice as fast in performing others. Generally speaking though, a 64-bit processor is faster than a 32-bit processor, which in turn is faster than a 16-bit processor. We will discuss processing speed in more detail under the Processor Paranoia section below. Operating Systems and Software Applications The software applications that you get for your computer must be compatible. Once you determine which operating system you are going to run on your new computer (assuming that you have a choice) you can then select which software applications to get. Most software applications are available in each of these flavors, so the application does not necessarily determine which operating system you have to use. If you buy a complete computer system from a single outlet store as opposed to purchasing each of the components separately from different outlets, the complete system will most likely come with an operating system preinstalled, such as Microsoft Windows XP or Linux.
Besides the operating system, you need to choose which software applications that you are going to need on your new computer. Most computer systems now come bundled with a suite of software applications, such as Microsoft Works,Microsoft Office, Corel Perfect Office, Lotus SmartSuite, or Sun Microsystems StarOffice. These suites of applications typically contain all the programs that you would need to run a small business. Microsoft Office comes with Word (word processor), Excel (spreadsheet), OutLook (calendar), PowerPoint (presentation graphics), and Access (database) in the professional version. Corel Perfect Office comes with WordPerfect (word processor), Quattro Pro (spreadsheet), CorelCENTRAL (calendar), Presentations (presentation graphics), Envoy (Internet publisher), and Paradox (database) in the profession version. Lotus SmartSuite comes with Lotus 1-2-3 (spreadsheet), Word Pro (word processing), Freelance Graphic (presentation graphics), Approach (database), Screencam (multimedia), and Organizer (time management software). Sun StarOffice comes with Writer (word processor), Calc (calculation and analysis), Impress (presentation graphics), Draw (graphics), Base (database), Schedule (time management software), Mail (E-mail program), and Discussion (news reader). Each package has its merits and I can't recommend one over the other. Other than a personal preference for the layout of one application over another, all of these are fine programs. In addition to the operating system and the business software applications, there are many other categories of software that you may or may not want to use on your computer. Software to access the Internet such as Microsoft Internet Explorer or Netscape Communicator, graphics applications such as Adobe Photoshop or Paint Shop Pro, multimedia editing software such as Adobe Premier or RealProducer Pro, and games should also be taken into consideration when choosing the brand and model of computer that you are going to purchase. Hardware There are literally hundreds of manufacturers for computers, monitors, printers, and other components. My advice to a first time buyer is to stick with a brand name. Getting that first computer can be very exciting, but the excitement can quickly dwindle to sheer terror and frustration if there are compatibility problems between the components and the software. The basic components of a computer system are the motherboard (containing the processor and memory), keyboard, mouse, monitor, diskette drive, CD-ROM drive, and hard drive. In addition to these, there are several other types of devices that you may or may not want to include in your computer purchase, such as a trackball, joy stick, modem, tape drive, zip drive, printer, plotter, scanner, sound card and speakers, TV card, video capture card, power supply backup, and surge protector. Whether you need any of these other devices or not will depend on which software applications that you intend to use. Also, if you are short on money when you buy your computer or decide that you need one or more of these items later on, you shouldn't have any problem installing these after the original purchase has been made, just make sure you buy components that are compatible with your system. I have had the opportunity to work with several different brands and models of computers, devices, and components over the years. The following is a list of computer components and their manufacturers that I have worked with and would recommend to others:
If you've already done some shopping around, you've discovered that you not only have to figure out which brand of computer to buy, but also what's inside. This is analogous to that first car you ever bought. You wanted that Corvette with the souped up 8-cylinder engine, but settled on the Ford Escort with the 4-cylinder engine. The processor is the "engine" that drives the computer, the bigger and faster the processor, the better the performance - generally speaking. The overall speed of a computer is affected by several things, but most notably the clock speed of the processor and the speed and size of the instruction/data bus. The clock speed is the rate at which the processor processes information and this is measured in millions of cycles per second (MHz) in older computers and billions of cycles per second (GHz) in newer computers. The way that this information gets to the processor is via the instruction/data bus. The instruction/data bus is the pathway for data communications between the computer's processor and the various components in the computer and is analogous to the buses that run in the city. The bigger the bus, the more people that it can carry. The faster the bus travels, the faster you get to where you want to go. Similarly, the computer's bus has a certain size or width called the data path which is measured in bits. The speed of the bus is also measured in MHz just like the processor. The larger the bus width and/or the faster the bus speed, the more data that can travel on it in a given amount of time. In addition, there is a thing called the cache that affects the speed of a computer. Before we go into detail on how the cache affects processor performance, lets see how a cache speeds up a web browser. The web browser that you are using right now to view this page also uses a cache to store the text and graphics that you see displayed. This information is stored temporarily in a folder on your hard drive. When you return to this page, rather than downloading the text and graphics again from this site, the browser just loads the information stored in the cache folder. This process speeds up access to web pages and graphics and also reduces traffic over the Internet. The cache in a computer is similar to the browser's cache in that it is used to store information temporarily so that the computer doesn't have to search around for it the next time that it is needed. There are two basic types of caches that speed up the computers overall performance, disk cache and memory cache. The disk cache is used to store the most recently accessed information from the computer's hard drive. In addition, it also includes information adjacent to the accessed information that is likely to be accessed. This reduces the time that it takes to read and/or write information to the hard drive. The speed at which a processor executes instructions depends on the cache memory. This cache memory simply remembers instructions and information that the processor has executed or accessed previously. There are two levels of cache memory and these are referred to by their location and degree of accessibility to the processor. The Level 1 cache (referred to as L1 or primary cache) is located on the same chip as the processor. This close proximity to the processor makes the L1 cache very fast. The Level 2 cache (referred to as L2 or secondary cache) is a separate chip on the computer's motherboard. Although it takes longer for the processor to retrieve information from the L2 cache than the L1 cache, the L2 cache is much faster than the computer's main (RAM) memory. The next time the processor needs to execute an instruction or load information that it has previously used, the memory cache supplies the data. If the information is not found in the L2 cache, the processor moves on to the computer's RAM memory. Besides the processors that are offered by AMD, there are several models from Intel that are available. From slowest to the fastest there is the Pentium, Pentium with MMX technology, Pentium Pro, Pentium II, Pentium III, and the Pentium 4. If we compared the speed of the Pentium through Pentium III processors, assuming that they all had the same clock speed, it would go something like this. The 200 MHz Pentium processor with MMX is about 28% faster than the 200 MHz Pentium, the 200 MHz Pentium Pro is about 20% faster than the 200 MHz Pentium with MMX, and the 233 MHz Pentium II is about 20% faster than the 200 MHz Pentium Pro (based on Intel's data). The 350 MHz Pentium II, based on the 100 MHz bus, is 20% faster than a 333 MHz Pentium II. A 1.5 GHz Pentium 4 is over 50% faster than a 1.0 GHz Pentium III. Intel also manufactures the Celeron processor (discussed below) and although I don't have any performance data, I would suspect that it would compare to the Pentium or perhaps the Pentium II.
Celeron The Celeron is a processor designed for the lower-end computer market. It has some of the characteristics of the higher-end Pentium class processors, but there are two big differences. First, the original Celeron processor used the older 66 MHz data bus. This 66 MHz bus model is still being manufactured today, but there is also a 100 MHz model. The second major difference is in the secondary or Level 2 cache (L2 cache). The first two Celeron processors (266 MHz and 300 MHz) did not contain any secondary or Level 2 cache (L2 cache). The 333 MHz Celeron and later versions contain a 128K L2 cache. Since the Celeron uses the older bus standard and has eliminated the L2 cache, it is cheaper to produce and thus cheaper for computer manufacturers to incorporate in their low-end computers. Also, since the L2 cache is not present in the Celeron, it uses the computer's main RAM memory exclusively to execute instructions. Depending on what you are using the computer for, this may or may not matter to you. The Celeron processor also runs at a lower frequency and has a lower operating temperature when compared to the other Pentium processors. Since it runs at a lower temperature, it requires a smaller heat sink (used to cool the processor). If a company decided to boost the performance of this processor by increasing the voltage (called overclocking), it would no doubt overheat down the road. Pentium 4 The Pentium 4 is Intel's latest and most powerful processor, with speeds in excess of 2.0 GHz. There are speed improvements for Internet applications that use streaming media (sound and video), 3D graphics enhancements for games and design applications, image processing including digital photography, digital video and content creation, speech recognition, engineering and scientific applications, and multitasking applications. This new processor is twice the size of a Pentium III, containing 42 million transistors, and is based on a new micro-architecture called NetBurst. The last time Intel introduced a new micro-architecture was in 1996 with the Pentium Pro. Other enhancements to the Pentium 4 based on this new architecture include 144 new multimedia instructions, better performance for multimedia applications (graphics and sound), dual channel RDRAM memory, 400 MHz system bus, Streaming SIMD Extensions 2 (SSE2), a new advanced Level 1 cache technology (Execution Trace Cache), and a new Hyper Pipelined Technology.
The Intel Xeon is directed at the high-end computer user and incorporates a larger and faster L2 cache and a new Slot 2 design. The Xeon has a 400 MHz bus and a 512 KB L2 cache. The Xeon MP has an additional 12 KB L1 cache (trace cache) and a new L3 cache. This third level cache is located in the processor and is used to provide a larger and faster data path to the computer's memory to reduce memory latency and increase throughput. Itanium The Itanium is a processor designed for high-end business use (CAD/CAM designing, large databases, security transactions, etc.). It has a 64-bit architecture which requires software written specifically for it (ex. Windows XP 64-Bit Edition). There are currently two types of Itanium processors available, the original Itanium (733 MHz and 800 MHz models) and the Itanium 2 (900 Mhz and 1.0 GHz models). The Itanium includes an integrated Level 3 cache (L3) which was first introduced in the Intel Xeon MP processor.
There are currently three different memory module types, the 72-pin SIMM (Single In-line Memory Module), the 168-pin DIMM (Dual In-line Memory Module), and the 184-pin DDR (Double Data Rate) DIMM and RIMM (Rambus DRAM) slots. The 72-pin SIMM memory transfers information over a 32-bit data path. The 168-pin and 184-pin DIMM and DDR DIMM memory transfers information over a 64-bit data path. The 184-pin RIMM memory transfers information over a 16-bit data path. As far as the type of memory that you install in the computer goes, there are several types and if you are a first time buyer, I would take whatever the computer comes with and not worry about it, it can get rather confusing. Suffice to say that RIMM and/or DDR DIMM memory is going to be the way of the future and that is what you want in your new computer if it is an option. As for the types of memory that you can install goes, there are memory modules that have either tin or gold plated connectors. The modules with the gold plated connectors are supposed to last longer and be a little more reliable than tin, but I've never had a problem with either type. Memory modules are available in the following five basic flavors:
From a purely performance point of view, the speed at which a computer can perform various tasks depends on a number of factors. These factors include things like the speed of the processor, the speed that data can be transferred between the processor and other components inside the computer (bus speed), and the speed of the computer's memory. While processor speeds have continued to double every 18-24 months and there have been improvements to internal bus speeds, computer memory has only seen modest speed improvements in the past few years. There are two schools of thought as to how to fix the memory problem. On one side is Intel with the Rambus DRAM memory solution and on the other side is everyone else pushing DDR SDRAM memory. The current memory standard at the time of this update for SDRAM is PC133 - memory operating at 133MHz. PC133 is capable of transferring data at 800MBs (800 MegaBytes per second). This is commonly referred to as the peak or maximum bandwidth. Considering the fact that SDRAM is only 75% efficient at transferring data at this rate, the effective transfer rate is limited to an effective or actual bandwidth of 600MBs (800MBs * 0.75). DDR SDRAM memory (PC266) operates at twice the speed of PC133 (133MHz * 2) and is capable of transferring data at 2100MBs. Since DDR SDRAM is only 65% efficient at transferring data at this rate, the effective transfer rate is limited to 1370MBs (2100MBs * 0.65). Rambus DRAM (PC800) is capable of transferring data at 1600MBs, but since it has a higher efficiency rating (85%), the effective bandwidth is 1360MBs (1600MBs * 0.85) - about the same as DDR SDRAM. Since DDR SDRAM and Rambus DRAM have essentially the same effective bandwidth, the main consideration at this point in choosing one over the other is price - Rambus DRAM is more expensive than DDR SDRAM. Both DDR SDRAM and Rambus DRAM require a 184-pin memory slot along with a special set of chips on the motherboard to access the memory. Computers with SDRAM memory can not be upgraded to DDR SDRAM or Rambus DRAM. Likewise, computers with either DDR SDRAM or Rambus DRAM can not use each others memory modules or SDRAM memory. Which type of memory do you need to get? For most people, SDRAM is still the cheapest solution for most computer applications (word processing, E-mail, surfing the Web, etc.). If you plan to use your computer for multimedia applications (image and sound development, graphics intensive games, etc.), either DDR SDRAM or Rambus DRAM is the way to go. ISA and PCI Bus Slots When you install new components in your computer, such as a graphics adapter card or internal modem, these adapter cards are installed in a slot on the computer's motherboard called a bus slot. Once installed, the adapter is then capable of communicating with the rest of the computer. There are two basic types of bus slots that are available, the ISA (Industry Standard Architecture) and the PCI (Peripheral Component Interconnect).
ATA (Advanced Technology Attachment) is the official name for the Integrated Drive Electronics (IDE) standard that hard drives use to communicate with the rest of the computer via the data bus. The original standard first defined in 1991 called ATA-1 defined the physical, electrical, transport, and command protocols for computer storage devices. There has been several revisions to the ATA standard, from ATA-2 (Enhanced Integrated Drive Electronics or EIDE) up to the latest standards known as Ultra ATA or Ultra DMA (ATA-4 and ATA-5). The Ultra Direct Memory Access (Ultra DMA or ATA-4) standard is an advanced version of the ATA-2 (EIDE) standard, which allows the drive to communicate at twice the speed of the older standard. The speed increase is achieved by reducing some of the delays inherent in the ATA standard and using Direct Memory Access (modes 0, 1, and 2) that allows the drive to access the computer's memory without intervention by the processor. Drives that conform to this standard will be listed as ATA/ATAPI-4, Ultra-ATA, Ultra-DMA, Ultra-DMA/33, or UDMA/33 and support data transfer rates up to 33MBsecond. The ATA-5 standard has additional DMA support (modes 3 and 4) using a special 80-wire, 40-pin Ultra-DMA data cable. The wires in an Ultra-DMA cable are shielded by a set of proprietary ground wires positioned between each signal wire. These additional ground wires reduces the amount of bus noise between the wires which enhances the hard drive's performance, speed, and reliability. Drives that conform to the ATA-5 standard will be listed as ATA/ATAPI-5, Ultra-ATA, Ultra-DMA, Ultra-DMA/66, or UDMA/66 and support data transfer rates up to 66MBsecond. The speed at which you can read and write data to a hard drive is based (partially) on the speed in which the hard drive platters spin. Currently there are four hard drive speeds available, 5400 RPM (revolutions per minute), 7200 RPM, 10,000 RPM, and 15,000 RPM. Serial ATA  Serial Advanced Technology Attachment (SATA) is a new standard for connecting hard drives in computer systems. SATA is based on serial signaling technology, whereas the older IDE hard drives used the Parallel Advanced Technology Attachment (PATA) standard since the 1980's. Advantages of SATA over PATA:
 Universal Serial Bus The Universal Serial Bus (USB) is a new industry-wide standard that will eventually replace the hassle of connecting parallel and serial devices to your computer. With USB, you don't need to worry about selecting the correct serial or parallel port, installing expansion cards, configuring the myriad of dip switches, IRQ (interrupt) settings, DMA (Direct Memory Access) channels, I/O (Input/Output) addresses, or the getting the correct settings for the device's software drivers. USB is Plug & Play with a twist, you never have to turn off the computer to connect or disconnect a device. You have virtually unlimited expansion capabilities without ever having to remove the cover off the computer. USB has an industry standard, one-size-fits-all connector that allows you to install and remove devices without opening the computer. Since this connector is hot swappable, you do not have to turn off the computer.
USB Specifications:
IEEE (Institute of Electrical and Electronics Engineers) 1394 is a new standard that is used by the computer manufacturers to connect various types of devices to your computer. In a lot of ways, 1394 is similar to USB in that they both are fairly new technologies, offer an alternative method to connect devices to your computer without the need to reboot, the ability to connect several devices to your computer, and both technologies use similar cables and connectors. The main difference between 1394 and USB is speed. The data transfer rate for 1394 devices is over 30 times faster than USB and this is expected to increase in the coming years. Eventually, 1394 will replace the serial, parallel, and SCSI ports on the back of a computer, but what happens to USB? 1394 and USB ports will both coexist on the computers of the future. Devices which do not require a high speed connection (such as keyboards, mice, keyboards, mice, monitors, joysticks, low-resolution digital cameras, low-Speed CD-ROM drives, and modems) will use USB ports. Devices that do require a high speed connection (such as hard drives, DVD-ROM drives, set-top boxes, digital audio and video, digital cameras, printers, and scanners) will use 1394 ports. The following table summarizes the current standards for 1394, USB, and SCSI:
A Digital Versatile Disc (DVD) is an optical, high capacity version of the CD-ROM. Up to now the CD-ROM has been limited to a maximum storage capacity of 650 MB of data, the new DVD discs will be able to store all of the information on 25 CD-ROMs and then some. There are currently three versions of the DVD, a standard single-layer, single-sided disc that can store 4.7 GB of data, a two-layer, single-sided disc that can store 8.5 GB, and a two-layer, double-sided disc that can store 17 GB. DVD will be used to store everything from computer games to software applications to full-length movies and will be similar in size to a CD-ROM or compact disc. The DVD drive will be able to read any CDs that you have now, but in order to take advantage of this new technology, you will need to get a DVD drive in your new computer. Accelerated Graphics Port The Accelerated Graphics Port (AGP) interface is a new bus specification developed by Intel. In order to use this new technology, you need an AGP video adapter card and a motherboard in your computer that has the special AGP connector (older computers can not be upgraded to AGP without changing the motherboard). At the time of this writing, most Pentium II class computers are being shipped with the AGP chipset, but make sure you check the specifications before buying to be sure. The way AGP works is that it enables software applications that use 3D images to dynamically access the computer's RAM memory to render and store information so that it can quickly be used to refresh the image displayed on the monitor. Access to the RAM memory is via a dedicated bus that runs independently of the computer's PCI bus and also has a higher bandwidth and faster transfer rate. The result is that 3D software applications not only run faster, but graphics are more lifelike. UMA vs AGP The purpose of the Unified Memory Architecture (UMA) was to move the graphics buffer that was used by software applications to render images from the dedicated memory on the graphics card to the computer's RAM memory. Since the cost of the video adapter card was a major consideration, the amount of on-board video memory was kept to a minimum, thus reducing the overall cost of the video adapter cards since video memory is more expensive than conventional RAM memory in the PC. AGP still assumes that there is some dedicated memory on the graphics adapter card to use as a buffer, but the computer's RAM memory is used to render memory intensive 3D images. The big difference between UMA and AGP is that the computer's RAM memory used with UMA must be allocated when the computer is booted up, thus reducing the total amount of RAM available to other software applications and decreasing performance. With ADP, once the image is rendered, the RAM memory is reclaimed by the computer's operating system and is then available for other software applications to use. Internet Service Providers A common phrase that you will hear when shopping for an Internet Service Provider (ISP) is up to, as in a connection speed up to 56K. This reminds me of the weekly car ads that I get in the mail which say that I qualify for up to $1,000 off a brand new car, which in reality is saying that I qualify for $0 to $1,000 off the list price and anything over $1,000 is out of the question. Keep this in mind when you are shopping around. There are several methods available to connect your home computer to the Internet. These range in cost from installing a simple modem in your computer for $25-30 to spending tens of thousands of dollars on optical fiber cable and the associated hardware. As with most other things, the more it costs usually the better (faster in this case) it is. The thing that you need to ask yourself is, is it worth spending $10,000 per month for a fast Internet connection to surf the web for recipes and do e-mail or can I get by with a $15 per month service that only provides a 56K connection. Before we get into the various types of services, a few definitions are in order. First off, the speed of an Internet connection or the data transfer rate, is measured in bits per second (bps). Modems will list their connection speed as Kbps (Kilo = thousand) bits per second. The faster services will either be listed as Mbps (Mega = million) or Gbps (Giga = billion). You will also see services described in terms of upstream and downstream data transfer rates. Upstream refers to the rate at which data is transferred from your computer to your ISP. Downstream refers to the rate at which data is transferred from your ISP to your computer. There are a couple different types of wiring that are used for Internet connections that you should be aware of, twisted pair or 10BASE-T (telephone cable) and coaxial cable or 10BASE-2 (cable TV cable). Twisted pair cable simply means that each pair of wires are twisted together, this reduces the amount of interference (called noise) that can affect the signal. Coaxial cable will usually be shielded which means there is a layer of material inside the cable to reduce interference. Modems A modem (modulator/demodulator) connects your computer to the Internet by modulating the digital signal from the computer to a carrier signal (audio). This audio signal is then sent (via the modem) over your existing telephone line to your ISP. Your ISP will have a modem that your modem is dialed in to that demodulates the signal back to digital, giving your computer the ability to connect to the Internet. The data transfer rate of a modem is limited by the telephone company's bandwidth which is about 3,000 Hz. If you upgraded from a 33.6 Kbps modem to one of the new 56 Kbps modems when they first became available, you seen a rather modest increase in your dialup connection speed at best. Theoretically, the maximum modem speed connection over a standard analog telephone line is approximately 35 Kbps, so a 33.6 Kbps modem connected about as fast as the telephone line would allow. I was getting a 31.2 Kbps connection with my 33.6 Kbps modem and after upgrading to a 56 Kbps modem, I got 31.2 Kbps. Remember what I said about up to.
If you are purchasing a 56K modem with your new computer, make sure that the modem uses the new K56flex technology or the modem's firmware is upgradeable. For more information on K56flex technology, see The Official 56K Modem Web Site. If you have a 56K modem that is not currently running the K56flex standard and need the firmware upgrade, see the V.90/K56flex Upgrade Central site. ISDN Like modems, Integrated Services Digital Network (ISDN) use twisted pair cable for the Internet connection. Where the modem uses your current analog telephone line, the telephone company will need to install a new digital line for ISDN. Typically the ISDN service is allocated in 64 Kbps channels, one channel gives you a 64 Kbps connection, two channels gives you a 128 Kbps connection. DSL DSL refers to Digital Subscriber Line and is a relatively new technology for home Internet access. DSL uses your existing telephone line, but is able to significantly increase the bandwidth over the lines between your home and the telephone company. This is one of the more attractive alternatives to using a modem, especially if you have two phone lines with one line just for computer use. DSL gives you 24 hour access to the Internet and does not interfere with incoming and outgoing telephone calls. In other words, your computer is connected to the Internet 24-hours per day, you can still use your telephone anytime you wish, and you only need one telephone line! There is a drawback to DSL however, you need to live less than 3 miles from the phone company's main office and the closer you are to the main office, the faster the data transfer rate. Data transfer rates range from 128 Kbps to 8.5 Mbps. Depending on the type of service that your telephone company supports, there are several options for DSL, which include Asymmetric Digital Subscriber Line (ADSL), Consumer Digital Subscriber Line (CDSL), EtherLoop, High Bit-rate Digital Subscriber Line (HDSL), ISDN based DSL (IDSL), Rate Adaptive Digital Subscriber Line (RADSL), Symmetric Digital Subscriber Line (SDSL), and Very High Bit-rate Digital Subscriber Line (VDSL). Cable Modems If you have cable TV and your cable company supports it, a cable modem may be an option for you. A cable modem uses your existing cable TV cable by allowing you to connect your computer (using a network interface card) to the set-top box that connects your TV to the cable. The upstream data transfer rate for a cable modem is 27 Mbps and around 2.5 Mbps downstream, but this depends on the cable company's connection to the Internet. Wireless The technology to connect a computer to the Internet via a wireless connection is fairly new. Some of the wireless connections available include General Packet Radio System (GPRS) which has connections speeds raging from 56 Kbps to 114 Kbps, Satellite which has a connection speed of 400 Kbps, Enhanced Data GSM Environment (EDGE) which has a connection speed of 384 Kbps, and the Universal Mobile Telecommunications Service (UMTS) which has a connection speed up to 2 Mbps. The problems with wireless connections are interference, noise problems, and bandwidth limitations. What Type of Configuration Do You Need Most computer systems, particularly the higher-end models, come in more than one configuration, desktop, mini-tower, or tower. The configuration you chose depends mainly on the amount of expansion you plan to do in the future. Most tower configurations tend to have a greater amount of expandability than do desktop models as well as larger power supplies to handle additional internal components, such as multiple hard drives, CD-ROM drives, and tape drives. Also, the amount of space that you have in your office or home needs to be taken into consideration. Tower configurations are made to be placed on the floor (except for the mini tower models), whereas desktop models are made to sit on the surface where the keyboard and monitor are located. Other than expandability and maybe a larger internal power supply, whether the computer is a desktop, mini-tower, or tower configuration, its still the same computer. Complete System Bundles Most stores, including mail order outlets, bundle various types of computer systems with a set of software applications. Some of these bundle deals include a printer, but most do not. If you are thinking about purchasing a bundled system, find out what exactly is included in the bundle as well as the manufacturers and models of the various components, such as the hard drive, modem, monitor, CD-ROM drive and speed, etc. Outlets that have bundled systems that appear to be a lot cheaper than other outlets are cheaper for a reason and usually this reason is not readily obvious. For example, around December 1995, my brother purchased the following bundle from a computer super store for $1349.99:
Sources for Information Based on the type of things you plan to do with your computer, you will have a set of minimum requirements that the software must have in order to do the tasks that you plan to perform at a reasonable or acceptable speed (I define an acceptable speed as being able to do a spell check in a word processing application faster than I can thumb through Webster's Dictionary myself). To find out what types of systems are available, the first place to start is by picking up a copy of one of the many computer magazines on the market or visiting their Web site, such as PC World, PC Magazine, or Byte, or one of the trade newspapers, such as InfoWorld or PC Week. These magazines and newspapers usually have articles comparing the various types and brands of computers as well as other components, such as monitors, modems, printers, and software. Use these ratings as a way to narrow down your list of options. One of the best sources for information is your friends and family members. See if any of them have a system similar to what you want to buy. Check to see if they have had any trouble with their system or have ever tried to get technical support from the system's manufacturer. Also see if they have ever had any compatibility problems with any software applications or hardware. The main things to look for are compatibility problems with the operating system, printers, and CD-ROM drives. If they have had compatibility problems, see what steps they took to get the problems resolved and how long it took to get the system working again. And finally, see if they would buy another computer system from this company. Another good place to check for information is the World Wide Web. Fire up your favorite Web browser, then in the locator field enter a URL in the format www.Company.com, replacing the word Company with the name of the company, such as www.compaq.com (Compaq), www.ibm.com (IBM), www.gateway.com (Gateway), or www.dell.com (Dell). Usually these hardware manufacturers, as well as most of the software and component companies, will have a complete listing of their line of products as well as the specifications. In addition to the World Wide Web, information on the various types of computer systems and software can also be found in the USENET newsgroups. If your Internet Provider gives you access to the USENET newsgroups, you can just click on one of the links below. If your provider does not give you USENET access, these newsgroups are available via the Web at www.remarq.com.
Before you walk into a computer store with money burning a whole in your pocket, make a list of the items (hardware and software) that you want in your new computer system and bone up a bit on the computer lingo. Prior knowledge as to what exactly you want and a knowledge of the terminology will help you when you meet with a salesman for the first time. A computer salesman, just like any other salesman, is going to want to sell you something - a computer. Their job depends on their sales ability and in some cases, have a certain quota of systems and/or peripherals they need to sell. By having prior knowledge of what exactly you want or don't want and having an understanding of the terminology will help you make a good decision on whether their system is right for you. If the salesman is not able to answer your questions or you feel like you are being pressured into buying the system that they want you to buy, find another salesman or just leave the store and come back another day. Remember, if you get talked into something that you don't really want, it's your own fault. If you are shopping for a computer for the first time, particularly if you've never used a computer before, do not buy the first thing you see. Get all the information that you can about the system or systems that you are interested in, then go home and do a little price comparison. A great way to compare the pricing of a system is to visit the Web site of one of the on-line computer stores that allow you to configure your own system. Two good sites for comparison are Dell and Gateway. These manufacturers have a wide selection of complete computer systems and allow you to configure your own computer on-line and then calculate the price. This should give you a pretty good idea whether the price you got at the store is a good deal or not. One thing to watch out for when buying a computer (or anything for that matter) is the old bait and switch ploy. The way this typically works is you are shown a super-duper computer system, usually a well known brand with all the bells and whistles. Once given the specifications on this one-of-a-kind system, you are informed that they also have an in-house brand of computer with the same specifications for a much cheaper price. By just saying that their computer is essentially the same as the brand name computer, most people assume that all of the specifications associated with the brand name computer apply to the in-house computer and leave it at that. When in fact, the only specification that probably does apply is that both systems run off electricity, although I wouldn't be surprised to find an in-house brand powered by a set of rubber bands. Most stores that deal in this type of activity don't stay in business too long and the two that I know of that used the bait and switch ploy in this area, are no longer in business. When you talk to a salesman, here are some basic questions that you should ask about the computer you are interested in, whether it is of the in-house variety or a brand name:
Some people feel so confused when it comes to buying a computer, particularly their first computer, that they don't want to have to make a decision and would just prefer that someone just tell them what to get (so they can blame them later). Do I want an Acer, AST, Compaq, CTX, Dell, Everex, Gateway, Hewlett Packard, Hitachi, IBM, Micron, Quantex, Swan, Toshiba, Zenith, Zenon, or should I go with that second mortgage and get a Silicon Graphics Onyx 3000? It can get pretty confusing, especially if you don't have a real good idea as to what you need. That is why I started this document out with having you ask yourself what am I going to be using the computer for. If I were buying a new computer today and I wanted to use it for some high-end graphics or multimedia applications, I would buy a 2.4 GHz Pentium 4. As far as the manufacturer of the computer goes, I've had pretty good luck with Gateway here at MSU, but we also have a lot of Dell and IBM computers. I would need a minimum of 512MBs for starters and two 36GB, 15k RPM, Ultra-2 SCSI hard drives. I would buy one of the high-end APG graphic adapter cards with at least 32 MBs of memory on the board for the graphics and I wouldn't buy anything less than a 22 inch, .26 dpi or .28 dpi SVGA monitor. The computer would also have to have the Universal Serial Bus and the High Performance Serial Bus (IEEE 1394) ports for future upgrades. For backing up the data on the computer, I would probably get a 80GB DAT tape drive. Another option for backing up data that I started using recently is a ReWritable CD-ROM drive. For the sound system, I would get a Creative Labs Sound Blaster Live! card with a set of surround sound speakers. I would also need a modem for surfing the Web, so I would get a USR 56K external modem. As for a printer, either an HP DeskJet or LaserJet, but a Cannon, Epson, or Lexmark color InkJet printer would be nice too. Now, on the other hand, if I was only interested in using word processing, E-mail, or just surfing the Web, I'd go with the cheapest Celeron class computer I could find. Here is what I would recommend for a low-end home computer system:
Once you have decided on a particular system, you just need to find out where you can get that system the cheapest. New computer stores seem to be springing up every day and stores that never dealt with computers before are suddenly offering their own brands of in-house systems and components. It would be nice to walk into a computer store, buy a system, then leave knowing that you will never have to go back there again unless you want to add something new to your system. This however, is generally not the case. Although there are quality checks during each phase of the production process in building a computer, there is still that one computer that slips through the cracks and this is the one you usually get stuck with (I'm speaking from experience here). I have probably purchased over 300 computers while working for the university and other than a sticky keyboard and a couple computers that came with dead hard drives, I've not had many problems. If you plan to purchase a computer system from a local store as opposed to one of the mail order superstore outlets, there are some things that you need to consider.
A few of the larger companies even offer technical support over the World Wide Web in the form of FAQ's (Frequently Asked Questions) or databases. For example, Microsoft's Web site contains two forms of information, the Microsoft Frequently Asked Questions which contains questions and answers to some of the most common technical problems and the Microsoft Knowledge Base which is a collection of over 50,000 detailed articles with technical information about Microsoft products, bug and fix lists, documentation errors, and answers to commonly asked technical support questions. In addition, Microsoft's Web site also has a software library which contains free software add-ons, bug fixes, peripheral drivers, software updates, and programming aids. Computer Stores Here is a list of some of the computer stores that are available via the Web that I have dealt with. These stores offer complete computer systems, components, and accessories:
To end this document, I thought I would pass on a few tips to help you be a smarter shopper.
Once you get your new computer, take some time to learn how to use it. Computers can be very frustrating, especially if this is your first one. There are literally hundreds of computer user groups and evening and weekend courses available at public schools, libraries, and colleges. Check the computer section of the yellow pages in your phone book or the local newspaper for the one nearest you. I teach a course here at Michigan State University that is targeted to first time computer users all over the world. This course is taught via the World Wide Web and as long as you have a connection to the Internet and an E-mail address, you can take this course. We cover everything from which mouse button to click to what makes a computer tick to creating a Web page. If you are interested, see Introduction to Home Computing (http://www.css.msu.edu/webclass.html). In Closing... We have discussed and defined several of the most important components of a computer in this document, but things are always changing. For the most part, this document only covers the computer hardware and software issues that I work with here at Michigan State University, so I am in no stretch of the imagination an expert. There are many other fine sites on the Web that are no doubt more current with the latest and greatest computer components and software. I encourage you to visit these other sites and by all means, make an informed decision when you buy. Good luck!
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