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6. Choosing a Computer


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6. Choosing a Computer

  1. 1. B.A. (Mahayana Studies) 000-209 Introduction to Computer Science November 2005 - March 2006 6. Choosing a Computer <ul><li>Considering the hardware choices involved in choosing a computer. </li></ul>
  2. 2. Overview <ul><li>1. How to Choose a Computer </li></ul><ul><li>2. The Processor </li></ul><ul><li>3. The Hard Disk </li></ul><ul><li>4. External Data Storage </li></ul><ul><li>5. Keyboard / Mouse </li></ul><ul><li>6. The Monitor </li></ul><ul><li>7. The Sound Card </li></ul>continued
  3. 3. <ul><li>8. Room for Expansion </li></ul><ul><li>9. Laptop Battery Life </li></ul><ul><li>10. The Printer </li></ul><ul><li>11. A Computer's Life </li></ul><ul><li>12. The Software </li></ul>
  4. 4. <ul><li>Decide how much to spend, and stick to it. </li></ul><ul><li>How will you use the computer? </li></ul><ul><ul><li>what software will you need? </li></ul></ul><ul><li>Hardware issues </li></ul><ul><ul><li>desktop or laptop? </li></ul></ul><ul><ul><li>processor, hard disk external storage, keyboard, mouse, monitor, sound card, printers, etc. </li></ul></ul><ul><ul><li>when to buy? </li></ul></ul>1. How to Choose a Computer
  5. 5. Windows XP <ul><li>Minimum hardware for Windows XP: </li></ul><ul><ul><li>Pentium 500 MHz processor, or higher </li></ul></ul><ul><ul><li>256 MB of RAM or more </li></ul></ul><ul><ul><ul><li>more memory is the best way to improve XP's speed </li></ul></ul></ul><ul><ul><li>4 GB hard drive (1.5 GB for XP) </li></ul></ul><ul><ul><li>a Super VGA monitor with (800x600) resolution </li></ul></ul><ul><ul><ul><li>try 1024x768 or higher with 24-bit colour </li></ul></ul></ul><ul><ul><li>CD-ROM or DVD-drive </li></ul></ul><ul><ul><li>keyboard and mouse </li></ul></ul><ul><ul><li>sound card and speakers </li></ul></ul>
  6. 6. 1.1. Lotus, July 2005 Free Items: printer, ink, table, chair, fax modem, 50 hours on Internet, speakers, cover, mouse pad, adapter, microphone, 10 CD disks, monitor frame and 3 others cover, mouse pad, adapter, microphone, speakers
  7. 7. Some Buzzwords <ul><li>DDR: Double Data Rate SDRAM; faster RAM </li></ul><ul><li>HDD: Hard Disk Drive </li></ul><ul><li>FDD: Floppy Disk Drive </li></ul><ul><li>CD-RW 52-32-52: </li></ul><ul><ul><li>the CD drive can write data at 52x speed, it can rewrite data at 32x speed, and it can read data at 52x speed </li></ul></ul><ul><li>USB: Universal Serial Bus </li></ul><ul><ul><li>a plug-and-play interface between a PC and devices such as hard drives, audio players, scanners, and printers </li></ul></ul>continued Others Later
  8. 8. <ul><li>AGP: Accelerated Graphics Port; speeds up 3D </li></ul><ul><ul><li>many companies sell AGP-compatible graphics cards </li></ul></ul><ul><li>10/100 LAN: Local Area Network </li></ul><ul><ul><li>dual speed 10/100 Mbps (bits/sec) with auto-sensing </li></ul></ul><ul><li>HT: hyper threading; multiple threads of execution </li></ul><ul><li>VIA: VIA Technologies, Taiwan; makes motherboards </li></ul><ul><li>FSB: Front Side Bus; links motherboard to the CPU </li></ul>
  9. 9. <ul><li>Chip makers assign model numbers or names to processors. </li></ul><ul><ul><li>the chip model indicates the processor’s architecture </li></ul></ul><ul><li>Each new model is faster, with other enhancements. </li></ul>2. The Processor
  10. 10. <ul><li>Pentium 4 with hyper-threading </li></ul><ul><ul><li>3.00 to 3.80 GHz </li></ul></ul><ul><ul><li>model numbers include 670, 660, 650, 640, 630 571, 570J, 561, 560J, 560, 551, 550J, 550, 541, 540J, 540, 531, 530J, 530, 521, 520J, 520 </li></ul></ul><ul><li>Celeron </li></ul><ul><ul><li>can do the same operations as the Pentium </li></ul></ul><ul><ul><li>less expensive, but slower </li></ul></ul><ul><ul><li>950 MHz to 2.80 GHz </li></ul></ul>Intel Chips
  11. 11. Intel Chip History <ul><li>1982: Intel 286 </li></ul><ul><ul><li>134,000 transistors, 12.5 MHz clock speed </li></ul></ul><ul><li>1985: Intel 386 </li></ul><ul><ul><li>275,000 transistors, 33 MHz </li></ul></ul><ul><li>1989: Intel 486 </li></ul><ul><ul><li>1.2 million transistors, 50 MHz </li></ul></ul><ul><li>1995: Pentium Pro </li></ul><ul><ul><li>5.5 million transistors, 200 MHz </li></ul></ul>continued
  12. 12. <ul><li>1999: Pentium 3 </li></ul><ul><ul><li>28 million transistors, 733 MHz </li></ul></ul><ul><li>2000: Pentium 4 </li></ul><ul><ul><li>42 million transistors, 1.5 GHz (1500 MHz) </li></ul></ul>
  13. 13. Part of Intel's Range in 2005 <ul><li>Desktop </li></ul><ul><ul><ul><li>PentiumExtreme Edition, Pentium D, Pentium 4 supporting Hyper-Threading, Pentium 4, Celeron D, Celeron </li></ul></ul></ul><ul><li>Notebook </li></ul><ul><ul><ul><li>Pentium M, Mobile Pentium 4 supporting Hyper-Threading, Mobile Pentium 4, Mobile Pentium 4 Processor-M, Celeron M, Mobile Celeron Processor </li></ul></ul></ul>
  14. 14. <ul><li>Clock speed </li></ul><ul><ul><li>indicates how many instructions can be processed per second </li></ul></ul><ul><li>Level 1 cache - cache built into the processor </li></ul><ul><li>Level 2 cache - the cache is on a separate chip </li></ul><ul><ul><li>faster than level 1 cache </li></ul></ul><ul><li>Benchmark tests </li></ul><ul><ul><li>a set of standard processing tasks that measure the performance of hardware or software </li></ul></ul>Factors Affecting Price
  15. 15. Processor Overall Performance : July 2005 from
  16. 16. <ul><li>The 'best' amount of RAM depends on the OS and applications you plan to use. </li></ul><ul><ul><li>at least 64 - 256 MB to run Windows XP </li></ul></ul><ul><ul><li>256 MB or more is better </li></ul></ul><ul><ul><li>a very good way of improving performance </li></ul></ul>2.1. How much RAM?
  17. 17. <ul><li>Storage capacity is measured in gigabytes (GB). </li></ul><ul><ul><li>get at least 40 GB </li></ul></ul><ul><li>Hard disk speed is usually measured in revolutions per minute (RPM) </li></ul><ul><ul><li>the higher the RPM , the less time you'll spend waiting for your computer to access files </li></ul></ul><ul><ul><li>best for desktops: 5400, 7200 RPM </li></ul></ul><ul><ul><li>best for laptops: 4200, 5400 RPM </li></ul></ul>3. The Hard Disk
  18. 18. <ul><li>Disk drives are classified by their type of controller </li></ul><ul><ul><li>the hardware that rotates the hard disk, and moves the read-write head </li></ul></ul><ul><li>Popular drive controllers are: </li></ul><ul><ul><li>Ultra ATA , EIDE, SCSI </li></ul></ul><ul><ul><li>Ultra ATA is twice as fast as EIDE </li></ul></ul><ul><ul><li>SCSI is slightly faster than EIDE </li></ul></ul>Hard Drive Controllers
  19. 19. <ul><li>Floppy disk drives are on their way out. </li></ul><ul><li>Rewritable CDs (CD-RW) are popular. </li></ul><ul><ul><li>increasingly with DVD support </li></ul></ul><ul><li>Many computers include USB ports for flash drives </li></ul><ul><ul><li>get a USB port supporting version 2.0 (potentially 40x faster than 1.1) </li></ul></ul>4. External Data Storage
  20. 20. Flash Drive <ul><li>Uses flash memory </li></ul><ul><ul><li>a rewritable memory chip that remembers its content without needing a power supply ( non-volatile ) </li></ul></ul><ul><li>A flash drive can be added/removed from the PC while the macine is switched on ( hot-swappable ). </li></ul><ul><li>Storage capacities: 64 - 256 MB </li></ul>
  21. 21. 5. Keyboard/ Mouse Microsoft’s Natural Keyboard may help prevent computer related injuries. Wireless
  22. 22. Mouse Types <ul><li>Mechanical, optical, laser mice </li></ul><ul><li>Cord or cordless? </li></ul><ul><li>How many buttons? </li></ul><ul><li>Mouse wheel? </li></ul><ul><li>Connector type </li></ul><ul><ul><li>serial port, USB port </li></ul></ul>
  23. 23. Laptop Input Choices Track point Trackball Touchpad
  24. 24. <ul><li>CRT (cathode ray tube) monitors use similar technology to television sets </li></ul><ul><ul><li>inexpensive and dependable </li></ul></ul><ul><li>LCD (liquid crystal display) monitors produce images by manipulating light within a layer of liquid crystal cells. </li></ul><ul><ul><li>compact, lightweight, easy to read </li></ul></ul><ul><ul><li>standard on laptops </li></ul></ul><ul><ul><li>flat-panel displays are available for desktops </li></ul></ul>6. The Monitor
  25. 25. <ul><li>Advantages of LCD </li></ul><ul><ul><li>display clarity </li></ul></ul><ul><ul><li>low radiation emission </li></ul></ul><ul><ul><li>portable </li></ul></ul><ul><ul><li>compact </li></ul></ul><ul><li>3x the price of a CRT </li></ul>Flat Panel Displays
  26. 26. <ul><li>Screen size is the measurement in inches from one corner of the screen diagonally across to the opposite corner. </li></ul><ul><li>The viewable image size (vis) excludes the screen's black border from the calculation. </li></ul>Monitor Sizes A monitor’s viewable image size is less than the screen size.
  27. 27. <ul><li>Dot pitch - a measure of image clarity </li></ul><ul><ul><li>smaller dot pitch means a crisper image </li></ul></ul><ul><li>Maximum resolution : the maximum number of pixels a monitor can display </li></ul><ul><ul><li>a typical max. resolution is 1280 x 1024 pixels </li></ul></ul>Monitor Resolution
  28. 28. <ul><li>Often the graphics card may be a part of the motherboard </li></ul><ul><ul><li>especially in laptops </li></ul></ul><ul><ul><li>the card should have 8 - 64 MB of video memory </li></ul></ul><ul><li>The most powerful graphics cards are used for 3D graphics </li></ul><ul><ul><li>sometimes called GPUs (graphics processing units) </li></ul></ul>Graphics Cards continued
  29. 29. <ul><li>The main 3D graphics card manufacturers are: </li></ul><ul><ul><li>ATI Technologies </li></ul></ul><ul><ul><ul><li>cards: Radeon 7/8/9000 Series, Radeon X Series </li></ul></ul></ul><ul><ul><li>NVIDIA Corporation </li></ul></ul><ul><ul><ul><li>cards: GeForce including GeForce FX Series, GeForce 6 Series, GeForce 7 Series </li></ul></ul></ul>
  30. 30. SVGA Graphics Cards <ul><li>Super Video Graphics Array (Super VGA or SVGA) is the most popular display type. </li></ul><ul><li>SVGA graphics cards have a standard resolution of 800x600 (480,000 pixels). </li></ul><ul><li>They should be able to offer resolutions up to 1280x1024, with 24-bit colour (16 million colours). </li></ul>
  31. 31. <ul><li>Passive matrix screen - relies on timing to make sure the liquid crystal cells are illuminated. </li></ul><ul><li>Active matrix screen - updates rapidly </li></ul><ul><ul><li>essential for crisp display of animation, video </li></ul></ul><ul><ul><li>found on newer laptops </li></ul></ul>Laptop Display Screens
  32. 32. <ul><li>A sound cards i mproves a computer's sound quality, and adds other sound capabilities: </li></ul><ul><ul><li>makes it possible to use speakers, a stereo, and a microphone to record and play sound </li></ul></ul><ul><ul><li>some sound cards also include MIDI </li></ul></ul><ul><li>Some sound card manufacturers </li></ul><ul><ul><li>Turtle Beach, Diamond, Creative Labs </li></ul></ul>7. Sound Cards
  33. 33. MIDI <ul><li>Musical Instrument Digital Interface </li></ul><ul><li>MIDI enables electronic instruments, such as synthesizers, samplers, sequencers, and drum machines, to communicate with one another and with computers. </li></ul>
  34. 34. <ul><li>When you buy a computer, make sure it has expansion options. </li></ul><ul><li>Motherboard expansion slots to add peripheral drivers. </li></ul><ul><li>Internal bays : mounting brackets in the computer case for devices. </li></ul>8. Room for Expansion continued
  35. 35. <ul><li>External bays : openings in the case so that devices can be (temporarily) connected to the computer. </li></ul>
  36. 36. <ul><li>PCMCIA expansion slots are found in many laptops. Classified according to size: </li></ul><ul><ul><li>Type 1 - thinnest, for memory expansion </li></ul></ul><ul><ul><li>Type 2 - for modems, sound cards, network cards (most common) </li></ul></ul><ul><ul><li>Type 3 - thickest, for hard disk drives </li></ul></ul><ul><li>Make sure the laptop has plenty of USB ports (2-6). </li></ul>Laptop Expansion
  37. 37. <ul><li>The length of time a laptop's battery will last depends on: </li></ul><ul><ul><li>the processor speed </li></ul></ul><ul><ul><li>the screen type (e.g. active matrix LCD) </li></ul></ul><ul><ul><li>how many peripherals are attached </li></ul></ul><ul><li>Hot swap : the ability to swap batteries while the computer is on. </li></ul>9. Laptop Battery Life
  38. 38. <ul><li>Details to consider when choosing a printer: </li></ul><ul><li>Resolution </li></ul><ul><ul><li>printer resolution is measured in dpi (dots per inch), the number of dots it can print per linear inch </li></ul></ul><ul><ul><li>more dpi means the final image will be clearer </li></ul></ul><ul><li>Colour capability </li></ul><ul><ul><li>can the printer support colour? </li></ul></ul>10. The Printer continued
  39. 39. <ul><li>Print speed </li></ul><ul><ul><li>print speed is measured by pages per minute (ppm) or characters per second (cps) </li></ul></ul><ul><ul><li>colour printing takes longer than black and white </li></ul></ul><ul><ul><li>text prints faster than graphics </li></ul></ul><ul><ul><li>ten pages per minute is a typical speed </li></ul></ul><ul><ul><li>duty cycle : the number of pages that can be printed per month </li></ul></ul><ul><li>Printer cost </li></ul><ul><ul><li>from $100 to $5000 </li></ul></ul>continued
  40. 40. <ul><li>Per-copy cost </li></ul><ul><ul><li>these are the ongoing costs for the printer, including ribbons, ink cartridges, and toner </li></ul></ul><ul><ul><li>the cost estimate assumes that a page uses an average amount of text, graphics, and colour </li></ul></ul><ul><li>Warranty </li></ul><ul><ul><li>how long does the warranty last for? </li></ul></ul><ul><ul><li>does it cover all printer parts? </li></ul></ul>
  41. 41. <ul><li>The most popular type of printer </li></ul><ul><ul><li>it produces low-cost colour and black-and-white printouts </li></ul></ul>Inkjet Printers Black ink cartridge Colour ink cartridge continued
  42. 42. <ul><li>The print head uses a series of nozzles that spray coloured inks onto the paper </li></ul>
  43. 43. <ul><li>The laser in the printer charges an electrostatically sensitive drum to accept toner which is then fused to the paper. </li></ul>Laser Printers
  44. 44. Features <ul><li>Higher quality output than inkjets </li></ul><ul><li>More expensive to buy than inkjets </li></ul><ul><li>Less expensive to operate than inkjet </li></ul><ul><li>The toner cartridge and drum cost approx. $70 </li></ul>
  45. 45. <ul><li>Dot matrix printers prints by striking groups of wires or thin rods onto an ink-coated ribbon against paper. </li></ul>Dot-matrix Printers?
  46. 46. Features <ul><li>Old/reliable technology: introduced in the 1970s </li></ul><ul><li>Low quality output </li></ul><ul><li>Can print onto multipart carbon forms </li></ul><ul><li>Used for “back-office” applications that need low operating cost and dependability. </li></ul><ul><li>A $4 ribbon can print 3 million characters </li></ul>
  47. 47. <ul><li>The lifecycle of a computer has five phases: </li></ul><ul><ul><li>product development </li></ul></ul><ul><ul><li>product announcement </li></ul></ul><ul><ul><li>introduction </li></ul></ul><ul><ul><li>maintenance </li></ul></ul><ul><ul><li>retirement </li></ul></ul><ul><li>Vaporware : computers (and software) that are announced but never produced. </li></ul>11. A Computer's Life
  48. 48. <ul><li>Toshiba Satellite </li></ul><ul><ul><li>Pentium M, 1.50GHz, 256MB RAM </li></ul></ul><ul><ul><li>60 GB Hard Disk </li></ul></ul><ul><ul><li>CD RW / DVD </li></ul></ul><ul><ul><li>modem </li></ul></ul><ul><ul><li>15.4 inch active matrix display </li></ul></ul>Price Drops over Time high price low price average price Weeks up to July 2005
  49. 49. Computer Companies <ul><li>Top-tier companies </li></ul><ul><ul><li>computer business for many years </li></ul></ul><ul><ul><li>Apple, Compaq, IBM </li></ul></ul><ul><ul><li>more expensive computers </li></ul></ul><ul><ul><li>responsible for many innovations </li></ul></ul><ul><li>Second-tier companies </li></ul><ul><ul><li>newer companies </li></ul></ul><ul><ul><li>Gateway, Packard Bell, Dell </li></ul></ul><ul><ul><li>less expensive computers, same quality </li></ul></ul><ul><ul><li>limited research and development </li></ul></ul>continued
  50. 50. <ul><li>Third-tier companies </li></ul><ul><ul><li>smaller startup companies </li></ul></ul><ul><ul><li>sell locally </li></ul></ul><ul><ul><li>less expensive </li></ul></ul><ul><ul><li>may use poorer quality components </li></ul></ul><ul><ul><li>more likely to go out of business </li></ul></ul><ul><ul><li>technical support depends on the owner </li></ul></ul><ul><li>Build your own </li></ul><ul><ul><li>readily available parts </li></ul></ul><ul><ul><li>relatively easy assembly </li></ul></ul><ul><ul><li>customize to your own needs </li></ul></ul>
  51. 51. <ul><li>Software publishers produce software </li></ul><ul><li>Alpha test : first phase of testing done in-house </li></ul><ul><li>Beta test : conducted by off-site tester </li></ul>12. The Software
  52. 52. <ul><li>The original version (release) of software is typically version 1.0 </li></ul><ul><ul><li>a new version is indicated by a new number (e.g. 2.0) </li></ul></ul><ul><ul><li>a new version is usually a major improvement </li></ul></ul><ul><li>Revision : a release that fix bugs or makes small changes </li></ul><ul><ul><li>the revision number is separated from the version number with a period (e.g. 1.1) </li></ul></ul>Software Versioning
  53. 53. <ul><li>Street price : average discounted price </li></ul><ul><li>Version upgrade price : discounted price for owners of an earlier version of the software </li></ul><ul><ul><li>must show proof to the vendor </li></ul></ul><ul><li>Competitive upgrade : special price for switching to a competitor’s product </li></ul><ul><li>Upgrading software is important </li></ul><ul><ul><li>less technical support for older versions </li></ul></ul><ul><ul><li>may lose eligibility for special pricing </li></ul></ul>Software Pricing Issues
  54. 54. Other Software Issues <ul><li>Compatibility with hardware/OS </li></ul><ul><li>Warranty </li></ul><ul><li>Technical Support </li></ul><ul><ul><li>help-lines, local user groups, personal service </li></ul></ul><ul><ul><li>Web-based technical sites, newsgroups, mailing lists </li></ul></ul>