Major Features
| No matter which type of laptop you have, you can be sure that it has a somewhat standard set of components. Later in this book we will discuss these components in more detail. ProcessorsThere has always been a range of processors available for laptops, but one rule has almost always applied: The fastest laptop is almost never as fast as the fastest desktop. The problem is one of power. Fast desktop processors run on AC power, of which there is a relatively limitless supply available. Portables in most cases at least occasionally must run on batteries, which have to be small enough so that the laptop can be lifted. Portable systems are also smaller than most desktops, and the tighter confines mean that the ability to run a high heat-producing processor is more limited. Therefore, a mobile processor in general has a more limited amount of electrical power available. Intel has responded to the needs of mobile systems by offering low-power "M" versions of its most popular processors. Figure 2.1 shows the Pentium 4-M chip, the mobile version of the Pentium 4. These processors are generally similar to the desktop versions except they use lower voltages internally and can adjust their clock speeds depending on the user's requirements. By lowering their voltages and clock speeds, these chips can cut their power requirements and thus extend a notebook's battery endurance. Note also that the maximum clock speeds of these chips are almost always slower than those of desktop chips. Figure 2.1. The Pentium 4 Processor-M chip from Intel. (Photo courtesy of www.intel.com.) Table 2.3 shows a comparison of the clock speeds of various mobile processors from Intel.
In March of 2003, Intel introduced its Pentium M chip for laptops, a part of its Centrino platform. The Celeron M followed as a low-cost version of the Pentium M. Unlike previous mobile processors from Intel, these chips are not a variation on a desktop chip, but a Pentium-compatible processor built from the ground up for mobile applications. Intel claims that laptop designers can achieve 1040% longer battery endurance if they use this chip. In addition to the chips' energy conservation, Intel also claims that the Pentium M and Celeron M are faster than they may appear. Because they use a different internal architecture, they are able to squeeze out more effective work during each clock cycle. As a result, you cannot directly compare the clock speeds of Pentium M/Celeron M and other mobile Pentium chips. For example, Intel claims that a typical laptop running a 1.6GHz Pentium M chip will race through benchmark programs 15% faster than a Pentium 4-M running at 2.4GHz. Intel also claims that this same laptop's batteries last 78% longer on the Pentium M than on the Pentium 4-M. Another processor specifically designed for portable applications is the Efficeon chip from Transmeta. This chip promises very low power consumption but at the expense of processing speed. The Efficeon has a different instruction set than Intel Pentium processors, requiring it to perform extra steps to translate the Pentium instructions into a form that the Efficeon can understand. Thus, although the Efficeon may have clock speeds comparable to Pentium M chips, its performance is considerably slower. Unfortunately, Transmeta has yet to capture much of the market and is concentrating more on licensing its power-saving technology rather than selling processors. Some laptop manufacturers occasionally opt for the highest performance possible by using desktop processors. As can be expected, these power-hungry chips result in surprisingly short battery endurance. Note, however, that this quest for desktop performance is never completely successful. Overall system performance depends not merely on the processor but on several other components, and as a result these devices have yet to equal the performance of the fastest desktops. You can find more information on mobile processors in Chapter 4. Video Display Size and ResolutionEver since the days of the luggables in the early 1980s, the design of portable computers has been highly dependent on the latest lightweight displays. When low-power LCDs became available, the development of the battery-powered laptop finally became possible. Today, the size of the display is the single most important determinant of the size of the laptop. Currently, virtually all laptops use active-matrix color displays. These screens provide needle-sharp images of high contrast, in most cases better than the CRT displays that most desktops use. Indeed, many desktop users are now upgrading to flat panels. The prime impetus for this switch may be to save space, but the improved image quality is at least a partial factor. There are, however, a few drawbacks to LCD displays. The first is that they have a fixed or native resolution. CRT displays can easily switch to higher or lower resolutions. When LCDs are moved above or below their native resolution, however, the image becomes decidedly blurry or even distorted. The second drawback of LCDs is their limited field of view. These displays may present high-quality images, but only to viewers sitting directly in front of the screen. People who may be sitting a few feet to the right or left of that optimal position may see an image where the colors have been shifted and the contrast lowered. With the increasing popularity of LCD televisions, some LCD manufacturers are developing screens that are more suitable for wide-angle viewing. If you plan to use your laptop for informal presentations, you should take a look at laptops that advertise wide-angle capability. Of course, some people prefer a more limited viewing angle because it makes it harder for other people to read your screen when you are working in public. One other downside of LCD screens is that they are considerably more expensive than CRTs. The good news here, however, is that the prices of LCDs have continually dropped over the years and will continue to do so. Indeed, the popularity of desktop LCD displays should lead to increased volumes and lower prices for both desktops and laptops. Because the technologies used in today's LCDs are basically similar, the main differences among screens have to do with their sizes, their resolutions, and their aspect ratios. Chapter 11, "Graphics and Sound," includes more detailed information on displays. Screen SizeSize is, of course, the most visually apparent property of an LCD screen. In general, as time progressed, screens became continually larger. There is, however, a size limit for laptops. As LCD screen sizes moved beyond 17 inches, measured diagonally, they became too large to be portable and were relegated to desktop use. In today's laptops, screen sizes vary from 7.2 inches (measured diagonally) for the smallest systems to 17 inches for the largest. The most common size is now 14.1 inches, which represents a good compromise between size and portability. In general, users are well advised to get the largest screen they can comfortably carry and afford. But note that for some screen sizes, there may be a choice of several different resolutions available. Choosing the wrong resolution may make the screen harder to read, or limit the amount of information that can be displayed. Screen ResolutionThe resolution of a screen depends somewhat on its size. As the size of the screen increases, it can comfortably accommodate more pixels, thus allowing for increased resolution. For 14.1-inch screensthe most common varietymost laptop manufacturers offer two choices of resolution: XGA and SXGA+. A few vendors also offer SXGA, but the unique aspect ratio (5:4) makes that size and resolution somewhat rare. The increased resolution of SXGA+ over standard XGA enables users to display nearly 87% more onscreen information such as folders, documents, web pages, and so on, at the same time. Increased resolution also increases pixel density (the number of pixels per inch of screen size), which in turn increases the apparent sharpness of photographs and graphic images. Some people even maintain that increased pixel density increases the readability of text. On the downside, however, increased resolution also decreases the size of standard text and icons on the screen. As personal preference varies, users should personally examine several different size/resolution combinations to see which seems best to them. Note that once you have chosen a resolution, it cannot be changed. A laptop's video circuitry can simulate a change in resolution, but the resulting image will be much less sharp than the image at the screen's original or native resolution. Table 2.4 lists common LCD screen sizes and the resolution they support.
Screen Aspect RatioThe aspect ratio for most laptop displays is the same as that for desktops and televisions: 4:3 (that is, the height of the screen is 3/4 the width). In the distant past, some laptops, such as the IBM PC Convertible and the Toshiba T1000, used wider display screens because that was all that was available. When 4:3 LCD screens came out, the public quickly gravitated toward this standard shape. Now, however, with the popularity of DVDs and high-definition TV, many manufacturers are installing widescreen displays on their systems (see Figure 2.2). These displays have a wider aspect ratio of 8:5 (16:10). Note that although this is much wider than the standard computer display, it is not quite as wide as the 16:9 proportions of HDTV, but is able to accommodate a full 16:9 HDTV picture within a 16:10 display with only a small upper and/or lower border (often used by the DVD player controls). Widescreen laptops are usually sold as multimedia or desktop replacement systems, due to their larger (and clumsier to carry) sizes. As more people use their laptops in home entertainment systems or as personal DVD players, expect this number to grow. Figure 2.2. The Dell Inspiron XPS Gen 2, with its 17-inch WUXGA display. (Photo courtesy of Dell Inc.) One interesting thing to note is that having a widescreen display doesn't necessarily mean you get more resolution or desktop screen real estate. For example, many so-called "widescreen" laptops have 15.4-inch WXGA (1280x800) displays. Personally, I would rather have a standard aspect ratio 15.1-inch SXGA+ (1400x1050) display because even though it doesn't have the "widescreen" aspect ratio, it actually offers an overall wider and deeper image in pixels than the so-called widescreen display. At the higher 1400x1050 pixel resolution, you'll actually be able to fit more open windows (web pages, applications, and so on) both in width and depth than you could on a WXGA screen. In fact, the SXGA+ screen has nearly 44% more overall resolution, meaning you can fit that much more content on the screen. The primary advantage of using a widescreen on a laptop is that human vision sees more peripherally than vertically, making wider screens better suited to what you actually see on them. Video AcceleratorsA crucial and sometimes overlooked aspect of computer performance is the speed of its video accelerator. This chip, shown in Figure 2.3, speeds up the process of moving pixels around the screen. Computer game players have been especially sensitive to the speed of their video processors because this can greatly influence the quality of their entertainment. But business users should also be aware that a video accelerator can impact tasks such as sales presentations. Figure 2.3. Video accelerator chips from NVIDIA. (Photo courtesy of www.nvidia.com.) Currently, the best laptop video accelerators are from ATI and NVIDIA. Note that as in the case of processors, laptop video accelerators are usually not quite as fast as those in desktop models. Typical video accelerators are listed in Table 2.5.
In addition to the type of video accelerator used, laptop users should also pay attention to the amount of video memory installed. The amount of video memory used for laptop graphics chipsets currently varies from 64MB to 256MB. In most cases the video memory is dedicated memory (separate from main RAM) used to hold information that will eventually be displayed on the screen. However, systems with video accelerators built into the motherboard chipset (such as the Intel Media Accelerator 900) use shared memory, which means that the video accelerator borrows main system RAM for video use. Since there is no dedicated video RAM, this results in a less expensive design (which also uses less power), but sacrifices performance when compared to dedicated video memory designs. The more video memory available, the more colors the laptop can display and the faster the video accelerator can operate. Large amounts of video memory are also useful for 3D graphics such as in games. Purchasers should be careful to note the type of video chipset and amount of video memory in a potential new notebook. Although there are a few select models with upgradeable graphics, in most cases the video accelerator components cannot be changed. You'll find more detail about mobile video chipsets in Chapter 11. Spindles (Storage)The classic three-spindle laptop is disappearing. These systems generally had three forms of rotating memory: a hard drive, an optical drive, and a floppy drive. Now, because floppy disks are so rarely used, many laptop manufacturers have been leaving them off in order to save weight and lower costs. In some two-spindle systems, the floppy can be swapped into the storage bay normally occupied by the optical drive, but you can't run both simultaneously. In most cases, the floppy is relegated to being used as an external device that connects to the system via a USB cable. Since floppy drives aren't used much anymore, this doesn't seem to bother many people, which is one reason the three-spindle designs are fading. As average file sizes continue to grow well past the capacity of a floppy, this once familiar component may well disappear altogether. Currently, most vendors offer external USB floppy drives for laptops as a $50 option. The most important drive in a laptop is its hard drive. Currently, drive sizes range from 20 to 160GB. Many experts suggest that users get as much hard drive storage space as they can afford. When users eventually purchase a digital camera or start storing audio and video on their hard drives, they will soon take advantage of all the storage space they have available. External USB drives can also be used to extend the storage of a laptop, and are actually quite excellent for backup, but when mobile, you generally have to rely on the drive that is installed internally in the system. Some laptops have drives that rotate at higher speeds than other drives. The use of faster rotating drives will positively impact system performance by a significant amount. A faster-spinning drive enables the system to access information from the hard drive more quickly. Faster drives also have a major impact on startup (boot) times, as well as the time it takes to hibernate and resume from hibernation. For some time there has been a variety of optical drives available for laptops. Most systems today include either a DVD-ROM drive, a combo DVD/CD-RW burner, or a DVD+/-RW drive, many of which can also handle DVD-RAM as well. In most cases these drives are not nearly as fast as their desktop counterparts, especially where DVD burning is concerned. In most cases if you plan on doing any significant DVD burning, I recommend attaching an external USB desktop DVD burner. Chapters 9, "Hard Disk Storage," and 10, "Removable Storage," discuss storage options in more detail. Expansion OptionsLaptop components are so tightly crammed together that few expansion options are available. Often the only way to expand the capabilities of a laptop is to insert a PCMCIA (Personal Computer Memory Card International Association) card (see Figure 2.4). These cards, also known as PC Cards or CardBus Cards, were originally designed as memory cards but are now capable of providing a wealth of features. Almost any feature not provided on a laptop or not provided in sufficient quantity can be added via a PCMCIA card. Figure 2.4. A diagram of the PCMCIA PC Card. Note that there are two types of PCMCIA cards and three sizes. In addition to the older 16-bit PC Card, there is also a high-speed 32-bit CardBus Card that is required for high-speed wireless networking cards. The three sizes are Type I, Type II, and Type III, which mainly vary in thickness (see Figure 2.5). Figure 2.5. An illustration of the three sizes of PCMCIA PC Cards: Type I, II, and III. Note that a Type III slot can accommodate a Type I or Type II card as well. Virtually all laptops have either a single Type III slot or two Type II slots stacked together so that they can also accommodate a single Type III card in the lower slot if necessary. Note that there are no Type I slots, and all laptops will take Type III cards in at least one slot. Because most of the capabilities formerly provided by these cards are now included as standard on the notebook's motherboard, many manufacturers have tried to save money by including only one Type III PCMCIA slot on their laptops. Although this does save a little on cost, it does limit the expansion capabilities of a laptop, in that you can install only a single Type I, II, or III card at any given time. A sampling of the different kinds of PCMCIA expansion cards available includes:
See "PC Cards (PCMCIA)," p. 289. See Chapter 8, "Expansion Card Buses," for more information on portable system expansion buses. External InterfacesA standard set of connectors for laptops includes a serial port and a parallel printer port. Because the devices that usually connect to these ports now are equipped with USB connectors, many laptop manufacturers are omitting these connectors. It is quite common for laptops now to have several USB 2.0 connectors. They can connect to a variety of external devices, including a keyboard, mouse, printer, scanner, storage drive, and even a USB hub to allow connection to more than two devices. A small number of laptops have IEEE 1394 (FireWire/i.LINK) connectors, RCA-style or S-Video connectors, and DVI interfaces. The IEEE 1394 connector, which is also known as FireWire or i.LINK, is mainly used to connect to digital camcorders. The RCA and S-Video connectors are used with TVs and VCRs. Most of the RCA, S-Video, or DVI connectors are video-out, but a few can also accept video input as well. The DVI interface is used with new display devices such as plasma TVs. Users who are interested in using their laptops for video applications should be sure that the necessary connectors are present. If they are not, they might be supplied via PC Cards. One connector that should be on all laptopslarge or smallis a standard analog VGA port. Without this, you will not be able to use your laptop with a video projector to make presentations. Pointing DevicesTraditionally, there have been three types of pointing devices: trackballs, pointing sticks, and touchpads. If you do not like the device on your current notebook, you can always add an external mouse via a USB connector. Chapter 13, "Keyboards and Pointing Devices," covers the various keyboard and pointing device options in detail. TrackballsTrackballs originally premiered on the Apple Macintosh Portable and soon appeared on several PC laptops. Because this type of pointing device takes up a relatively large amount of space, both in terms of its footprint and its height, it has been dropped from laptop designs. TrackPoint (Pointing Sticks)Pointing sticks originally premiered on the IBM ThinkPad but soon became a standard feature on many Toshiba, Dell, and other laptop systems. This device, which looks like a colored pencil eraser placed in the middle of the keyboard, can be accessed by the user without moving his hands from the keyboard (see Figure 2.6). IBM refers to it by the trademarked name TrackPoint. Figure 2.6. The IBM TrackPoint, the original pointing stick. (Photo courtesy of IBM, www.ibm.com.) TouchpadsTouchpads originally debuted on the short-lived Gavilan, one of the first laptops. Laptop designers particularly like them because they take up so little space. Beginners or casual users like them because they are easy to use; however, experienced laptop users do not find them nearly as fast or accurate as a TrackPoint. Two manufacturers make most of the touchpads in use: Alps and Synaptic. Many reviewers prefer the Synaptic touchpad because its sensitivity can be adjusted. If the touchpad is too sensitive, you can activate it simply by floating your thumb a few millimeters above the surface, something that happens frequently during typing. Combination Pointing DevicesSome laptops offer two pointing devices: a touchpad and a pointing stick. This is a great idea because many users have strong preferences for either one or the other device. The combination enables manufacturers to offer a single laptop that appeals to both groups of users. Docking OptionsAll portable computers entail some type of compromise. One way to lessen that compromise is to purchase a docking station. Most laptops have available both a full-function docking station and less expensive port replicator. Laptop users can quickly snap their laptops into either of these devices and suddenly endow their systems with additional capabilities. Unfortunately, port replicators and docking stations are not standardized in the industry; the connectors and physical formats are proprietary to the various manufacturers. This means that a port replicator or dock for one system will most likely not work with another, unless it is a compatible model from the same manufacturer. Most manufacturers that make port replicators and docking stations available try to make them work with multiple different models or even different product lines. For example, the same port replicators and docks work with several different series of ThinkPad laptops, so if I upgrade from an R40 to an R52 or even a T43, I can continue to use the same docking stations and port replicators that I currently own. In addition, I can use many of the same peripherals, such as AC adapters as well. This interchangeability makes upgrading to a new system less expensive overall and helps to maintain my loyalty to the ThinkPad brand. Many bargain laptops do not have available port replicators or docking stations. Since I connect many devices to my laptop when I am working at my desk, I would personally never purchase a system that did not have at least a port replicator available because it would be far too inconvenient for my needs. On the other hand, if you rarely plug external devices into your laptop or never move it from a stationary location, then a port replicator or docking station might be something you could live without. Docking StationsDocking stations are designed by laptop manufacturers to provide laptops with many of the advantages of desktops. The exact features provided by a "dock" vary from one model to another. Some provide a wealth of storage options, such as extra hard drives and optical drives. A few will also provide desktop-style expansion slots. These slots can be used with a wide array of unusual expansion cards, such as signal-acquisition cards. Port ReplicatorsPort replicators are designed to provide some of the benefits of docking stations at a low cost. One of the chief benefits of these devices is to make it easy to quickly connect a laptop to a number of external devices. For example, when many users take their laptop roaming, they need to disconnect and then later reconnect their external monitors, keyboards, mice, printers, network, and phone lines. With port replicators, all they need to do is connect those devices to the port replicator a single time. Then they can simply dock and undock their laptop from the replicator as needed. Port replicators are a major convenience item, even if a laptop is used only at home. For example, I have no less than 14 external devices continuously connected to my laptop when it is at my desk, and with a single push of a button I can disconnect it from the port replicator and work wirelessly anywhere in the house, garage or yard. I would never consider purchasing a laptop that didn't have an available port replicator. Note that there are generic USB-based port replicators available for laptops that don't have a port replicator option; however, they are often problematic, don't support many types of connections, and in general are a poor substitute for a true port replicator or dock. NetworkingIn the laptop domain, networking components used to be relegated to PC Card add-ons, but as the need to attach a portable system to a network has increased, so have the networking options associated with portable systems. Networking options for mobile systems are covered in Chapter 12, "Communications." Wired NetworkingMost recent laptops are equipped with internal LAN adapters that allow them to be connected quickly to any Ethernet network. This enables quick and easy connections to LANs in the office or cable and DSL modems at home. This connector is also useful in hotels where broadband connections are present. Most of the newest laptops include gigabit (1000Mbps) Ethernet support as well. If a laptop is not equipped with an internal LAN adapter, users can still provide this capability by inserting a PC Card LAN adapter. Because of the high speeds required for 100Mbps or gigabit LAN connections, these cards will normally come in a 32-bit CardBus adapter. Wireless NetworkingAt first an interesting novelty, wireless networking is quickly becoming an essential standard feature for laptops. For a slight investment in hardware, a wireless LAN (WLAN) offers the user the ability to have a high-speed connection to a local LAN or to the Internet while roaming anywhere in the office or at home. On low-end systems where internal wireless network adapters are not standard, most laptop manufacturers are pre-installing wireless LAN antennas as standard equipment in their laptops. This allows the system to be wireless upgradeable via the installation of an internal Mini PCI either at purchase time or any time in the future. Note that there are three different types of wireless LAN technologies: 802.11a, 802.11b, and 802.11g. Unfortunately, these standards are not all compatible with one another. To ensure greater compatibility, WLAN products can be certified by the Wireless Fidelity (Wi-Fi) Alliance. 802.11aDespite its name, 802.11a was actually the second wireless LAN standard to appear. Being second, it also has the advantage of being faster (54Mbps) and of providing more channels for laptops to use. The disadvantage is that this equipment is more expensive than that of the more popular 802.11b technology. Because this standard supports more channels (and therefore more simultaneous users) and is less susceptible to interference from devices such as microwave ovens, it is the WLAN of choice for large office buildings. 802.11bOriginally, 802.11b was the most popular WLAN standard, available in many offices, homes, and even coffee shops. Unfortunately, it is also the slowest, with a nominal throughput rate of 11Mbps. Note that 802.11b is not compatible with 802.11a and that both require different types of antennas. Also note that 802.11b is vulnerable to interference from devices such as microwave ovens and wireless phones. Many laptops were equipped with 802.11b. For those laptops and notebooks not already equipped, an assortment of inexpensive 802.11b PC Cards is available. 802.11gA newer variation of 802.11b, 802.11g is as fast as 802.11a yet is also backward compatible with the large installed base of 802.11b equipment. Because of this compatibility, 802.11g has replaced 802.11b in most new installations. Note, however, that because it uses the same spectrum as 802.11b, it is vulnerable to the same interference from microwave ovens and wireless phones. Therefore, many users in high-density areas might still opt for 802.11a. 802.11nA new standard currently under development is 802.11n. This standard will offer up to 10 times the speed of 802.11g, operate over greater distances, and should be backward compatible with both 802.11g and 802.11b devices. The 802.11n standard uses a feature called multiple-input multiple-output (MIMO), meaning multiple transmitter and receiver antennas to allow for increased data throughput and range through multiplexing signals over several antennas at once. This standard is not expected to be completed until November of 2006, and it may be some time after that before certified products are available. Beware of products advertised as "MIMO" or "pre-n" only because they do not technically conform to this standard and may not be upgradeable to true 802.11n when the standard is finalized. Until Wi-Ficertified 802.11n products are available, I recommend sticking with 802.11g for most uses. CombinationsNot sure which standard will prevail? Would you like to cover all bases? Some cards offer the option of handling all three standards. These are called 802.11a/b/g dual-band/tri-mode cards. They are available both as internal Mini PCI cards as well as CardBus cards. Most laptops today include dual-mode 802.11b/g cards or tri-mode a/b/g cards.
See "Wireless LANs," p. 601. Wide Area NetworkingThe problem with all the 802.11 standards is that they have limited range, usually less than about 300 feet. If you want coverage over a greater area, in places such as a client's office or a parking lot, you can use directional antennas or range extenders to increase the range. Another option is to connect using a WAN (wide area network) via the cellular phone network. Users can easily connect to a WAN by purchasing a wireless modem PCMCIA card and setting up an account with a local cellular service. Some users may also be able to use their cellular phones as wireless modems through either a Bluetooth or USB connection. Infrared (IrDA ) is another type of wireless connection that is useful for slow-speed, short range, line-of-sight communications, especially for printing to IrDA-capable printers. However, be aware that not all laptops nor all printers have IrDA capabilities, so look for this feature in both laptops and printers if you feel it is something you might use.
See "Wireless Modems," p. 597. |
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