Tài liệu PC World Hardware Tips pptx

Speed: A USB 1.1 controller transfers data at up to 12 mbps, or about four times faster than the speediest parallel port and 100 times quicker than a serial port.. Even old devices run o

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AGP’s strength is its ability to process texture maps Certain 3D games and a few 3D graphics development tools are currently the only programs that benefit greatly from fast-moving texture maps

To make sure you’re getting the full benefits of AGP 4X, go into your CMOS setup program and make sure your PC is set to run at AGP 4X rather than 2X Load the latest AGP drivers onto your

PC The AGP drivers that come with

Win-dows 9x are limited, and systems using

AMD’s Athlon CPU don’t work well with older drivers Check with the manufac-turer of your PC, motherboard, or chip set—in that order—to find updated driv-ers and installation instructions

Hardware Tips welcomes your tips and ques-tions and pays $50 for published items Kirk Steers is a PC World contributing editor.

tem’s CMOS setup program to see these statistics But we’ve found a handy work-around: Just use Alex van Kaam’s Moth-erboard Monitor freeware utility to keep watch over your PC’s fans, voltages, and temperatures Head to find.pcworld com/16020to download the program AGP 3: WORTH THE UPGRADE?

I REPLACED MY 1X/2X AGP graph-ics card with a 2X/4X AGP adapter, but my graphics performance has not improved Should I have waited for the AGP 8X cards to come out?

Evan Nathan, Dallas

absolutely not.Applications that take full advantage of AGP 8X transfer speeds are at least a year away Other improve-ments to third-generation AGP graphics cards should enhance graphics

perfor-mance, however FIGURE 1 shows the

max-imum transfer rates of the AGP versions

K I R K S T E E R S

HARDWARE TIPS

A Cool Breeze Keeps Your

PC’s Innards From Frying

biggest temperature changes occur when you turn your system on and off, so leave your PC on but use its power-manage-ment functions to keep its innards as cool

as possible when it’s idle When you turn

on your computer in a really cold office, let the system warm up for 15 minutes before saving anything to its hard drive

Listen to your fans:Your PC keeps cool by blowing a constant stream of air through its case The primary air mover in most PCs is the power-supply fan, although some systems have an additional ventila-tion fan built into the case Even in rela-tively clean offices, dust can accumulate

on the fan intakes and seriously obstruct airflow Clean your PC’s fans and fan intakes regularly, especially if you hear a change in the fans’ one-note whir

Most CPUs also have a cooling device—

either a fan or a heat sink (A heat sink is

a metal plate with fins or spikes intended

to dissipate heat.) If your CPU’s fan or heat sink stops functioning properly, a CPU failure won’t be far behind

A heat sink needs a constant flow of air

to remove heat In most PCs, the internal fans provide the required airflow Never leave the case off your system while it’s running Going topless may lower the overall temperature inside your PC, but it also destroys the internal airflow patterns that keep your CPU and other compo-nents from overheating

Mercury rising:Most PCs made in the last few years monitor and report on the state

of their case, CPU, and power-supply fans Some also provide data on the sys-tem’s internal temperature, and some have a temperature alarm built into their BIOS You usually have to open your

sys-154

do the cold,dark days of winter have

you dreaming of tropical beaches, sunny

deserts, and the inside of your PC? You

read right The climate inside your

com-puter can rival that of Death Valley in the

summer, and triple-digit temperatures

are bad news for your hardware

Most desktop PCs run comfortably

when their internal temperature is

be-tween 60 and 110 degrees Fahrenheit

(Check your system documentation to

find your PC’s exact range.) Internal

tem-peratures over 110 degrees can stress

del-icate circuits and electrical contacts,

which may substantially shorten your

computer’s life Hard drives are

especial-ly vulnerable when the temperature goes

up: Data transfers slow down, and data

written to the disk is more likely to be lost

Here’s how to beat the PC heat

Avoid ups and downs:Sudden changes in

temperature are just as harmful to your

PC’s circuitry as high temperatures The

FIGURE 1: FASTER AGP rates speed up tex-ture maps but won’t help most applications.

DOES YOUR CURSOR sometimes appear

and disappear, move in the wrong

direc-tion, or change size and shape? It could

be a sign of mouse trouble, which is

often due to a conflict with your graphics

card’s driver If you use Windows 9x or

Me, there may be a solution simpler than

installing an updated driver Open

Con-trol Panel, double-click the System icon,

choose the Performance tab, and click

the Graphics button Move the slider

next to Hardware Acceleration one notch

to the left This change disables some

graphics capabilities, but it may be the

solution to your rodent problem.

A CONFLICTED MOUSE

Transfer speed (MB/second) AGP SPEED

AGP 1X AGP 2X AGP 4X AGP 8X

266 533 1066 2133

AGP DATA TRANSFER RATES

K I R K S T E E R S

HARDWARE TIPS

For Fast, Easy Computing,

USB Is the Bus to Ride

CONNECT DEVICES

WITH A USB HUB

A UTILITY FOR CACHE MANAGEMENT

AN OLD AGP CARD

IN A NEW AGP SLOT

ial or parallel port often requires a com-plicated configuration USB avoids the hassles of setting and juggling IRQs and other resources One IRQ covers all the hardware attached to each

USB port USB peripherals have fewer compatibility problems than peripherals using serial or parallel ports

Speed: A USB 1.1 controller transfers data at up to 12 mbps, or about four times faster than the speediest parallel port and 100 times quicker than a serial port

While that won’t affect the performance of a mouse or joystick, it makes a big dif-ference with printers, scan-ners, and other data-hungry peripherals

Portability: All USB devices can be hot-swapped, which means that you can plug

a piece of hardware into your PC, or un-plug one, while your system is running

The operating system will automatically recognize and configure new USB devices

Support for old hardware:There once was a lack of USB peripherals, but now almost every I/O device comes in a USB version

Even old devices run off USB by using an adapter that converts parallel, serial, and other devices to USB Belkin and SIIG are two vendors that offer such adapters

One port, many devices:With the use of a USB controller, a single USB port can theoretically support up to 127 different devices, although practically speaking, it’s unlikely you’ll ever run more than ten

154

l o t s o f t h i n g s get better with time:

friendship, a fine cabernet, and yes, even

PCs Every day we’re bombarded by

ad-vertisements hawking systems that are

faster and cheaper—so much so that it’s

easy to lose sight of really useful

improve-ments, like the Universal Serial Bus

USB is the way to connect anything to

your PC It’s fast, simple, and so much

better than parallel and serial ports that

they look downright medieval by

compar-ison (Not to say that leeches and a good

suit of armor don’t come in handy every

now and then But, hey, enough about my

personal life.) Judging from all the e-mail

I get about problems with parallel and

serial ports, a surprising number of you

still aren’t aware of just how great USB is

And with USB 2.0, the spec gains even

more advantages Here’s a rundown on

why you should be riding with USB

Ease of use:USB just works better

Peri-od Getting hardware to function on a

ser-peripherals at one time All the devices connected to a USB 1.1 controller have to share its 12-mbps bandwidth If you need

to run multiple devices that eat up more than 12 mbps, you can use a PCI adapter card to add a USB controller to your PC

Belkin sells a USB 1.1 PCI adapter card for $39 and a USB 2.0 version for $59

Easy linking:If you’ve ever tried to chain together two devices—such as a printer and a Zip drive—you know it can be a real nightmare USB allows any device to be connected to any other USB device that has a built-in hub So you’ll never have to crawl under your desk to reach the back

of your PC when attaching a peripheral

Some keyboards and monitors have built-in hubs with one or two USB ports

If you don’t already have one of these, consider buying a dedicated USB hub

that sits on your desktop Dedicated hubs have clusters of two, four, or more ports

Belkin’s four-port USB 2.0 hub, for

exam-ple, costs as little as $52 online (see

FIG-URE 1) If your hub connects lots of USB devices to your PC, make sure you have adequate power to run them all Printers and many similar devices have their own power connections, but mice, keyboards, modems, and others get their power from the USB connection If the devices need more power than the USB port can

deliv-er, the entire bus may shut down When this happens, Windows displays a warn-ing icon next to the Universal Serial Bus Controller entry in Device Manager For-tunately, you can avoid power problems

by using the right type of USB hub

Bus-powered USB hubs draw

electrici-H E R E ’ S electrici-H O W

FIGURE 1: EASILY ADD AND REMOVE USB hardware by installing a USB hub such as Belkin’s four-port device.

WHEN YOUR PC uses the same chunk of

data over and over, it often stores that

piece of information in fast memory, or

cache, where it can retrieve the data

faster than it can off a hard drive

Stor-ing the right amount of data in the cache

can improve your PC’s performance.

Outer Technologies’ $10 Cacheman is an

excellent shareware utility that lets you

conveniently monitor memory use and

control your cache settings Go to find.

pcworld.com/17641 to get the download.

SPEND YOUR CACHE WISELY

If you buy a self-powered hub, make sure it provides a full 500 mA to each port—some don’t To check, divide the hub’s total amperage rating (found in its documentation or on the power supply)

by the number of ports For example, a four-port hub should provide at least 500

mA per port, or 2 amps total

If your PC originally shipped with Windows 98 or later, it almost certainly has a set of working USB ports Look on

the back of your PC for two narrow, rec-tangular openings If you have an older system without USB, an adapter card should get you up and running (Using USB on systems running Windows 95 is,

at best, problematic If that’s what you’re using, consider an OS upgrade.) Many PC peripherals now support the USB 2.0 specification USB 2.0 devices can run more than 40 times faster than those using USB 1.1 The top USB 2.0 data rate is 480 mbps, which is faster than the IEEE 1394 (FireWire) ports that run hard drives, digital still and video

cam-eras, and CD-RW drives (see FIGURE 2).

USB 2.0 products are backward com-patible, so you can use older USB devices

on a USB 2.0–equipped PC So what’s the catch? USB 2.0 products are a bit more expensive Also, the selection of USB 2.0 devices is limited at present, and they re-quire a USB 2.0-ready PC to run them Look for the first USB 2.0–ready moth-erboards and systems to hit the

mar-ty from the incoming USB connector and output up to 100 mA per port (that’s milli-amps, a measure of electrical current)

Self-powered hubs draw their own power

or, in the case of the root hub in your PC, get it from the PC They provide up to 500

mA per port Keyboards, mice, and other low-power USB devices use 25 mA to 40

mA and run well on a 100-mA port of a bus-powered hub More-demanding de-vices need to use a self-powered hub

FIGURE 2: USB 2.0 HARDWARE MOVES DATA slightly faster than devices using an IEEE 1394 (FireWire) connection, but it can be more than 40 times faster than USB 1.1 devices.



Maximum data rate (mbps)

Comments SPECIFICATION

USB 1.1 USB 2.0 IEEE 1394 (FireWire)

12

480

400

Supports low-speed (up to 1.5 mbps) peripherals such as mice and keyboards, as well as printers, scanners, and other medium-speed devices.

Also called High-Speed USB, the new standard is fast enough to support external hard drives, CD-RW drives, and other high-speed peripherals.

Popular spec for digital video cameras; will allow direct connection of IEEE 1394 devices (such as a DVD player to a TV) without the signal having to pass through a PC.

USB VS FIREWIRE DATA RATES

ket sometime this spring You can add

USB 2.0 functionality to your system now

by using one of the adapters mentioned

above But before buying a USB 2.0

prod-uct, check with the vendor to confirm the

availability of USB drivers for your

oper-ating system As I write this, USB drivers

for Windows XP are still unavailable, and

drivers for Windows 98 and Me aren’t

always included with USB products

ANY AGP PORT IN A STORM?

MY BROTHER JUST gave me his

old Pentium III PC minus a graphics

card I opened up its case to add

the AGP 2X graphics card I took from my

for-mer computer, but the AGP slot in the P-III

PC is much longer than the slot in my old

system Can I safely add my old graphics card

to the newer computer’s AGP slot?

Peter Miller, Topeka, Kansas

you probably can, but before adding

an old AGP card to a new motherboard,

make sure the two are compatible

There are three different types of AGP slots: the original AGP 1.0 1X/2X slot, the AGP 2.0 2X/4X slot, and the AGP Pro slot The 1X/2X version is the shortest and can be distinguished from the 4X type by a small separator that divides it into two sections The 4X slot also has extra pins at one end

From your description, your PC proba-bly has an AGP Pro slot These slots have

an extension added to the end of the 4X slot without the extra pins While the AGP Pro slots are designed for top-end graphics cards costing over $1000, they are also found frequently on mother-boards used in mainstream PCs

Because the AGP Pro slot is backward compatible, a 1X/2X or 2X/4X AGP card will work in the slot But take care when inserting a 1X/2X card to avoid

incorrect-ly inserting it into the AGP Pro extension

Often these extensions come with a cover

to prevent this, but the covers can fall off

Also make sure your graphics card and

motherboard support the same operating voltages The original AGP 1.0 spec called for motherboards and cards that operate

at 3.3V, and the AGP 2.0 spec added sup-port for operation at 1.5V If your old graphics card operates at 3.3V, you’ll need

a motherboard that supports 3.3V AGP Likewise, a card that runs at 1.5V needs a corresponding AGP slot

Fortunately, many motherboards come with ‘universal’ AGP slots that support either voltage, and many of the latest graphics cards support both voltages as well Not all setups do, however A few motherboards out there run exclusively at 1.5V and won’t support the older 3.3V cards Check with your motherboard and graphics card vendors to determine your hardware’s precise requirements

Kirk Steers is a PC World contributing editor Reach him at kirk_steers@pcworld.com Hardware Tips welcomes your tips and ques-tions and pays $50 for published items.

K I R K S T E E R S

HARDWARE TIPS

Will a New CPU Give

Your PC More Vroom?

THE INS AND OUTS

OF CPU UPGRADES

MATCH UP YOUR MOTHERBOARD

FASTER WRITING TO REMOVABLE DISKS

That’s because other components play

a big role in determining your system’s overall performance For example, dwin-dling hard disk space or too little RAM can slow down a system that’s trying to process big spreadsheets or databases

And adding a topflight graphics card to your PC can dramatically improve the look and play of many games

But if you’re on a tight budget and you need a moderate, across-the-board perfor-mance boost, adding a new CPU can be worthwhile Our rule of thumb: If you’re staying in the same processor class, buy a CPU upgrade only if it will at least double your current clock speed—from 400 MHz

to 800 MHz, for example Better yet, move up an entire CPU class, such as from a Celeron chip to a full-fledged Pen-tium II or PenPen-tium III

If you have an older system, keep in mind that powerful new PCs are cheaper than ever If a CPU upgrade costs more than $300, you may be better off spend-ing a little more for a new PC

Here’s what you need to know about your PC before you buy a new CPU:

What’s your old CPU’s name?Use Intel’s Processor Frequency ID Utility to identify the company’s CPUs Go to find.pcworld

com/11880to download the program

What’s your PC’s chip set? The chip set your motherboard uses determines what types of CPU, RAM, hard drive, and other hardware will work with your PC To dis-cover what chip set your PC uses, look in your system’s manual or download and run a hardware diagnostic program such

198

i f y o u t h i n k you can feed your need

for PC speed without investing in a whole

new system, simply by replacing your old

CPU with a newer and faster one, you’re

right—probably A CPU upgrade can be

a cost-effective way to boost PC

perfor-mance, but it’s not for everyone Any

prospective upgrader should ask two

questions: How much performance will a

new processor add to my PC? And is the

bounce worth the cost?

You can find a CPU upgrade for almost

any PC—from systems based on Intel’s

ancient 80486 chip through today’s

Pen-tium III models But don’t expect

mir-acles from a new CPU if its clock speed is

only slightly higher than that of your

cur-rent CPU A new processor running at

twice the clock speed you’re used to won’t

come close to doubling your system’s

formance A 10 to 20 percent jump in

per-formance is more realistic

as the HWInfo shareware package Visit

find.pcworld.com/11881to get it

Does it use a socket or a slot?The type of CPU connector your motherboard uses determines which CPUs can connect to your system FIGURE 1lists information to help you determine what your PC uses

What about your frontside bus and multi-pliers?The frontside bus (or FSB) is the path between your RAM and CPU It runs at a particular frequency: 66, 100, or

133 MHz The motherboard multiplies that frequency to drive the CPU For ex-ample, a Pentium II-233 CPU typically runs on a motherboard with a 66-MHz FSB and a multiplier of 3.5 The same sys-tem can run a Pentium II-266 CPU if you change the multiplier from 3.5 to 4 But running a Pentium II-400 CPU on that system would be a waste: With an FSB of

66 MHz and a top multiplier of 4, the old machine can run no faster than 266 MHz

What is the voltage?If you’re adding a standard CPU rather than an upgrade processor, make sure your motherboard’s CPU voltage matches the voltage needs of your new CPU Some motherboards sup-port multiple CPU voltage settings, but many older boards don’t Check your manual to be sure of what you need

Kirk Steers is a PC World contributing editor Hardware Tips welcomes your tips and ques-tions and pays $50 for published items.

H E R E ’ S H O W

FIGURE 1: KNOW YOUR motherboard attach-ment type before you buy a CPU upgrade.

IF YOU FREQUENTLY use a removable

storage drive—such as an Iomega Zip or

Jaz drive—you can speed up data writing

to the drive by enabling write-behind

caching This arrangement allows

Win-dows to temporarily store data destined

for the disk in RAM and then write it to

the disk when no other tasks are being

performed To enable this option, launch

Control Panel’s System applet, select

Performance•File System•Removable

Disk, and check the Enable write-behind

caching on all removable disk drives box.

MORE ZIP FOR YOUR ZIP

Motherboard attachment CPU

Pentium (75 to 133 MHz) Pentium (133 to 200 MHz) Pentium MMX Pentium Pro Pentium II Pentium III Celeron (300 to 433 MHz) Celeron (466 MHz or faster) K5

K6, K6-2, K6-III Athlon Athlon (Thunderbird) Duron

Socket 5 or 7 Socket 7 Socket 7 Socket 8 Slot 1 Slot 1 or Socket 370 Slot 1 or Socket 370 Socket 370 (PPGA or FC-PGA) Socket 5 or 7

Socket 7 or Super 7 Slot A Socket A Socket A

WHAT’S YOUR SOCKET?

grounded outlet

Always remove all traces of the old device before you install the new one Here’s what to do:

1.Use the Add/Remove Programs applet

in Control Panel to remove all of the soft-ware associated with the device

2 Remove the device’s driver.

Click Start•Settings•Control Panel•

System, choose the Device

Manag-er tab, double-click the device’s

category, select the device you’re

uninstalling, and click the Remove

button Note: To remove the driver

of a graphics card (Windows calls

it a “display adapter”), first double-click the device name, choose the

Driver tab in its Properties box,

and select the Update Driver

but-ton; then use the Update Device Driver Wizard to install Windows’

generic VGA driver (see FIGURE 1)

3 Shut down your PC.

4 Open your system’s case, and remove

the old device If you’re upgrading your graphics card, put the new one in now

5 Restart the PC and check Device

Man-ager If the old device’s entry is still there, repeat the uninstall Sometimes

you have to “remove” a device more than once before there are

no traces of it left in Windows

Install new devices one at a time, and use your PC for a few days between each installation to give problems time to reveal themselves Some things to re-member as you install:

1 Plug and Play isn’t always the

best method for installing a device Some drivers have their own installation programs that are best run independently of

e v e r y t i m e y o u crack open your PC’s

case to add or remove hardware, you’re

rolling the dice Maybe you’ll slip that new

modem or ethernet card into its slot and

watch Windows seamlessly install its

driv-ers Yeah, and maybe your Internet stocks

will return to triple-digit share values,

too—but I sure wouldn’t count on it

Even with such technologies as Plug

and Play, hardware

can still be quite

tricky to install

Mistakes or

prob-lems can lead to

hours of

trouble-shooting, or even

to an unusable PC

These installation

guidelines should

help keep your

system running

First, create a

backup Windows

98 automatically

backs up its Registry

files every day By default it stores the last

five backups in the Windows\Sysbckup

folder as cab files named rbxxx.cab,

where xxx is the number of the backup—

001, 002, or whatever Copy the most

re-cent cab file, and give it a different name

so it won’t be overwritten by a corrupted

copy If you need to restore a backup file,

restart your system in DOS mode and run

regscan.exe—running it from a DOS

ses-sion in Windows won’t work

Windows Me’s System Restore utility

automates system backups Click Start•

Programs•Accessories•System Tools•System

Restore to reload a system configuration

that Windows saved previously

Last, make sure that you’re electrically

grounded Even a small static charge on

your body can damage your PC’s delicate

circuitry Touch the system’s metal

chas-sis just before you unplug it from its

Windows’ own installation routines

2 If the installation instructions are

unclear or refer to a different model num-ber, go to the manufacturer’s Web site and look for updated documentation

3 Get the latest driver update The drivers

on the floppy or CD-ROM that came with the device may be out-of-date Check the vendor’s Web site for newer versions

4 Don’t interrupt a driver installation.

Stopping in midprocess can cause all kinds of trouble If you want to abort an installation, finish the procedure com-pletely, and then uninstall the driver

5 Secure cards to the case with their

fas-tening screws Unfastened cards can work their way out of their slots over time

For additional hardware tips, visit www.pcworld.com/heres_ how Send your tips and ques-tions to kirk_steers@pcworld.com We pay

$50 for published items Kirk Steers is a

PC World contributing editor.

Reserve a Cab

ABOUT THE ONLY time you need your Win-dows CD-ROM once your PC is running is when you install hardware If you can’t find the disc, or if you can’t get your CD-ROM drive to work, you could be stuck To play it safe, make a folder on your hard disk, name

it CABS, and copy Windows’ cab files (the compressed versions of Windows operating system files) to it Just copy the ‘win98’ and

‘drivers’ folders from the Windows CD They occupy about 275MB, but it’s space well used, even if you only need the files once.

Your PC’s Case:

Enter With Caution

FIGURE 1: BEFORE INSTALLING A NEW graphics card, replace the old driver with Windows’ Standard VGA driver.