Guide
to Buying a Desktop Computer
Buying a PC can be a tricky and finicky experience.
Even for seasoned PC veterans it can be hard to keep abreast of the latest
technologies. With the constant influx of new interface technologies, faster
processors, bigger and better RAM and increasing hard drive sizes, it's
a hard decision to know when to upgrade to a new model or invest in that
second PC.
As well as ensuring you know exactly what
you are talking about and what you need to ask when you go to shop online
or in a retail store, this guide will also help you to keep your purchase
costs down so you don't spend any more money than you need to.
It's worth pointing out that how much you
do spend on your PC depends on what you want to do with it. There is no
need to buy a souped-up computer with a massive hard drive, and a powerful
graphics card or processor if all you want to do is maintain the finances
for your small business. Alternatively, if you wish to use your PC to edit
your digital videos, store lots of digital images or download massive files
from the Internet, then buying a PC with all of these attributes makes sense.
The PC processor
At the heart of your PC lies the central
processing unit, a key determinant of the performance of your system. Street
prices of processors can range from $170 for a budget processor to over
$1,600 for a top-of-the-line processor.
In the past, the speed of a processor was
indicated by what is called it's clock speed, which is measured in gigahertz
or GHz (1000MHz equals 1GHz). The clock speed appeared in the naming of
the processor: Pentium4 2.2GHz, for example.
Most of today's new CPUs, however, are given
abstract model numbers that give no indication of the clock speed and are
used to determine the speed of the processor relative to other processors.
An Intel Pentium D 830 is better than an Intel Pentium D 820, for example,
although the model name does not tell us by how much. It may have a faster
clock speed, a bigger cache or some other advantage over the 820.
AMD uses a somewhat different method to describe
its CPUs. It describes them based on their performance relative to an Intel
CPU (Intel being the dominant market player).
The processors you will most likely encounter
in desktop PCs are the Intel Pentium 4 5xx, 6xx and 8xx, and the AMD Athlon
64 and Athlon 64 X2. These two series of processors represent the performance
end of the market; while AMD's Sempron and Intel's Celeron processors are
targeted a budget-conscious buyers.
Here's a brief breakdown of the processors
on the market:
Intel processors
Last year, Intel changed its processor number scheme, abandoning the MHz
rating in lieu of an abstract model numbering scheme. Now Intel processors
are arranged in families, such as the 3xx (Celeron), 5xx (Pentium 4), 6xx
(Pentium 4 EM64T) and 8xx (Pentium 4 dual-core) families. Within a given
family, the higher the number, the faster the processor; for instance the
Pentium 4 660 runs at 3.6GHz, while the Pentium 4 630 runs at 3.0GHz. If
you find the new numbering scheme confusing, don't worry - most sellers
will be more than happy to tell you the MHz speed of any processor they
are selling.
Intel has a chart that breaks down the processor
numbers on its web site.
The four main families of Intel desktop consumer
processors break down as follows:
The Celeron (3xx) processors are entry-level
CPUs, designed for low-cost systems. They don't have as much internal memory
("L2 cache") as other Intel CPUs.
The Pentium 4 (5xx) processors are the mid-range processors. They are faster,
on a clock for clock basis, than Celerons, but mostly lack 64-bit extensions.
If the last digit is a "1", such as in the Pentium 541, it means
the processor actually does have 64-bit extensions.
The Pentium 4 EM64T (6xx) processors have 64-bit extensions, similar to
those found in the AMD Athlon 64. They're best used with the new 64-bit
version of Windows XP, which can make the most of their extra power.
The new Pentium 4 dual-core (8xx) range essentially has two 6xx processors
on a single packaged chip, effectively making the system a dual-processor
system (even though it only has "one" CPU). The Pentium 4 dual-core
processors require motherboard with a supporting chipset, such as the Intel
945/955X chipsets.
All of these current Intel processors fit into LGA755 motherboards, although
you will need a supporting chipset if you plan to install an 8xx processor.
AMD processors
In its consumer line of products, AMD has
boiled its vast collection of different products down into three core models:
the Sempron, the Athlon 64 and the Athlon 64 X2. You may still see the rare
Athlon XP around, but we recommend avoiding them.
AMD has an unusual naming schema, basing
its product names not on the actual MHz rating of the processor, but on
the MHz rating of an Intel processor of equivalent speed. For instance,
the Athlon 64 3000+ only runs at 2160MHz, but because it is as fast as a
3,000MHz Intel Pentium 4 (because of improved processing efficiency), AMD
call it the Athlon 64 3000+. This is done to reduce confusion for buyers
deciding whether to buy Intel or AMD. And if you're worried that AMD are
highballing their comparative speeds, don't be - if anything, the AMD processor
speed equivalents are conservative. As an added bonus, the naming schema
aligns the AMD processors, making it easier to choose between different
types of AMD processors (for instance, it makes it easier to decide whether
to buy Sempron or Athlon 64, because both processors are rated on the same
scale).
The Sempron is AMD's answer to the Intel
Celeron. It's a very low cost processor based on the Athlon XP. It lacks
64-bit extensions. It fits in a Socket 754 motherboard.
The Athlon 64 is AMD's mainstream and high-end processor. It has 64-bit
extensions (which require a 64-bit version on Windows to make the most of).
Some use 754-pin sockets, others 939. Check which you have before buying
your motherboard.
The Athlon 64 X2 is a dual-core processor, integrating two Athlon 64 CPUs
on a single piece of silicon, effectively making it a dual-processor system
on a chip. Unlike the Intel dual-core solution, the X2 does not require
a special chipset, and should run on any Socket 939 motherboard (although
many motherboards will require a software "BIOS" upgrade).
Dual processors and dual-core processors
Dual processor motherboards are usually only found in server setups and
high-end desktop PCs that use the functionality for intense graphics CAD
and design work. Therefore, dual processor boards aren't really applicable
to the consumer desktop PC market. However, the recent introduction of dual-core
processors by both Intel and AMD is bringing multiprocessing to the masses.
A dual processor system is exactly what the
name implies - a system with two processors. You need a motherboard with
two processor sockets to make this work (and such motherboards tend to be
expensive). A dual-core processor is a little different, however. A dual-core
processor is a single chip that has multiple processing "cores"
on it. It will appear to the operating system as two processors, act the
way two processors would act and have the same kinds of advantages as a
dual-processor system has. It is only one chip, however, and only requires
a single standard socket on the motherboard.
AMD's Athlon 64 X2 (which has the memory
controller on the chip), should work in any Socket 939 motherboard, although
most require a BIOS upgrade. Intel 8xx dual-core processors (which leave
memory control to the motherboard's chipset) require a supporting motherboard.
Currently, high end processors from both
Intel and AMD are shipped as dual-core models. As the year progresses, both
companies expect that the bulk of processors shipped will be dual-core models.
Hyper threading
Hyper-Threading technology is now found in
most P4 2.8GHz and above chips, but was initially introduced to desktop
PCs through the newer P4 3GHz in early 2003. Hyper-Theading is a technology
developed by Intel to improve the performance of the processor by increasing
its efficiency. It does this by pretending that it's two processor instead
of one, so the operating system throws more work at it. It's not to be confused
with dual-core processor however - a Hyper-Threading processor still only
has one core; it's just pretending that it has two.
Some Intel processors are both Hyper-Threading
and dual core, and will thus appear as four processor to the operating system.
The motherboard
The motherboard tends to be overlooked when purchasing new individual components
or a PC package as a whole. Most people first check the processor and its
clock speed, then the size of the hard drive, and perhaps check which graphics
controller is lurking inside. Considering the motherboard is essentially
the backbone of your PC, attention should be paid to this component as it
will shape the longevity of your PC system.
If you're unsure what a motherboard looks
like, a quick peek inside your PC will set you straight. It will invariably
be the biggest single item in there. It not only plays home to your processor
and memory, but all your expansion cards: your graphics card, your hard
drive and CD-ROM connectors, plus external ports. The motherboard also houses
the BIOS (Basic Input/Output System) that controls the simplest configuration
of your machine.
The BIOS also performs the POST (Power on
Self Test) health check when you switch on your machine. This is a diagnostic
testing sequence that begins as the PCs power is turned on. If the components
are configured correctly, the PC will continue booting into the operating
system.
Motherboards for AMD and Intel
A motherboard, in almost all circumstances,
will only support one type of processor, such as Intel's Pentium 4, or AMD's
Athlon64. Different chips have connectors that vary physically from one
another. It ensures that you can't plug the wrong chip into the wrong board
by accident.
The motherboard chipset
The second way in which motherboards differ
is in the chipset they use. If you think of the motherboard as the physical
hardware, the chipset is the logic that underlies it. It is the part that
dictates how different components actually talk to one another and controls
the features and abilities of the motherboard.
Processor development and chipset design
go hand in hand - so much so that the chipset is built to support the facilities
offered by a certain processor. There are a number of chipset vendors on
the market, with the five main companies being Intel, AMD, VIA, NVIDIA and
SiS. Intel and AMD only produce chipsets for their own processors, while
VIA, NVIDIA and SiS make chipsets for both companies.
Chipset manufacturers have produced a large
range of chipsets, based on a variety of north bridge and south bridge types.
The most recent, and most advanced, releases for Intel processors are the
Intel 945/955X chipset (which support the dual-core processors), the NVIDIA
nForce4, the SiS655 and the Via PT894.
For AMD motherboards, look for recent chipsets
including the NVIDIA nForce4, the SiS761 and the Via K8T890.
Below, we've included a list of many chipsets
you might see appear in motherboards right now.
Motherboard slots
Although some motherboards support different
features, several key components are present on all current models. Each
will be designed to take either a socket or contact-based processor and
there will be memory module slots for either DDR SDRAM or DDR2 SDRAM. There
will also be expansion slots so you can add extras like sound and graphics
cards; support for the hard and DVD+/-RW drives; and, finally, connectors
for keyboard, mouse and peripherals.
Motherboards with built-in sound and graphics
It's also quite common for motherboards to
have some built-in basic sound or graphic capabilities. Take note: integrated
graphics obviate the need for a separate graphics card but generally offer
poor 3D games performance in comparison. This is because integrated graphics
use system RAM to run, which takes away from overall system performance.
Integrated audio, on the other hand, is often
quite good, with some sound chips handling digital output for up to 8 channels.
If you only want to use office applications,
then an onboard graphics chip should suffice; die-hard gamers, on the other
hand, should install a dedicated card.
For more on motherboards you might like to
read our motherboard buying guide.
Interfaces
Universal Serial Bus
Universal Serial Bus (USB) is a standard
for connecting peripheral devices to a computer. It was designed to replace
PS/2, serial and parallel connections (which still appear in many motherboards).
The first incarnation of USB, version 1.1 operates at up to 12Mbps (which
means the peripherals can talk to the computer, and visa versa, at 12Mbps),
while the newer USB 2.0 delivers up to 480Mbps.
With USB, you can often connect one device
to another in a daisy-chain fashion. Thus, a mouse can connect to a keyboard
instead of plugging into the back of the computer. And that keyboard can
connect to a USB port in the monitor. If you need more USB ports, just connect
a hub and in theory, up to 127 USB devices can be interconnected.
Low-power USB devices can sometimes be directly
powered from the PCs power source via the USB connection, but only when
the device draws less than 5v.
You would expect to see at least 4 USB ports
on the rear faceplate of a motherboard but latest release motherboards have
up to 6 ports, with two located on the front of the case.
Firewire
IEEE 1394, which is commonly referred to
as FireWire (but also as i.Link by Sony), is used to connect devices such
as digital video cameras to your personal computer at a speed of 400Mbps.
FireWire supports up to 63 devices on a single bus.
A newer version of FireWire is referred to
as IEEE 1394b. The architecture of the new specification technically supports
speeds up to 3.2Gbps, but initial implementations only work at 800Mbps.
However, the biggest change for FireWire may not be the doubling of speed,
but the range provided by the specification. The current version of FireWire
works at a distance of 12-15 metres. The 'b' spec will increases that distance
up to 115 metres.
S/PDIF (Sony/Philips Digital Interface)
Developed jointly by the Sony and Phillips
corporations, S/PDIF allows the transfer of digital audio signals from one
device to another without having to be converted first to an analog format.
Headphones
A port for a 3.2mm audio jack, usually green,
used to connect external headphones. Usually located on the motherboard,
some PC cases may have a pass-thru cable with an additional connection on
the front.
Microphones
Similar to the headphone jack, this is a
(usually pink) 3.2mm audio port to connect external microphones. Pass thru
cables are also used here for connection at the front of the PC.
Line in
A connection that is used to input an audio
signal into your PC. For example, you can connect your stereo's CD player
to it and listen to it through your PC. Simply connect an audio lead from
your CD player through to the sound card and output the audio to a set of
5.1 speakers connected to your PC.
Parallel
A 25-pin data transfer port used predominantly
for connecting printers.
Serial
Game controllers and older-style dial-up
modems would normally use this type of 9-pin connection.
PS/2
Typically used for connecting a mouse and
keyboard. Easy to identify, these 6-pin ports are often coloured green for
mice, purple for keyboard.
Memory
Random Access Memory (RAM) is the term used to describe memory found on
PCs or graphics controllers (more on this later). Memory is incorporated
into a desktop PC via memory modules, which connect through dedicated memory
slots on the motherboard.
The most commonly used type of RAM in PCs
is Double Data Rate (DDR) SDRAM. Single Data Rate (SDR) SDRAM is still available
for older systems is becoming increasingly rare. SDRAM also differs in the
physical sense, SDRAM DIMMs will not physically fit into a DDR RAM slot
and visa versa. Both are implemented into the system as DIMMs (Dual Inline
Memory Modules). DDR memory will always give your system or graphics card
better performance than SDR memory. This is because DDR, or double data
rate RAM, sends two data bits on every clock pulse. DDR II memory has also
been recently released with improved speeds and heat spreaders to keep the
memory cool.
DIMMs come in different flavours - PC100
and PC133 for SDRAM, and PC2100, PC2700, PC3200, PC4000, PC4400 for DDR
SDRAM. DDR II RAM is also available from PC3200 up to PC6400. The numbers
relate to the speed at which the memory modules can operate (although the
DDR numbers use a different measuring system, so it is impossible to compare
the two types of memory through listed speeds alone). Your motherboard must
support the type of memory you want to use. Currently only some Intel boards
use DDR2.
Graphics controller
Graphics controllers are the devices that
connect to and tell monitors what to display. They also take over many of
the processing tasks associated with rendering and displaying 2D and 3D
graphics. By taking over many display-related tasks from the CPU, the graphics
controller allows the CPU to focus on other tasks without affecting overall
system performance. They vary considerably in price and capabilities. You
can pay as little as $50 for one, or over $1,000.
Onboard graphic controllers
Not every PC you buy will have a dedicated
graphics controller. You will generally find that in small form factor PCs
- that is, physically smaller systems - there is not enough space to have
a dedicated graphics controller. The normal practice in such a case is to
integrate sound and graphics on the motherboard. The end result may be a
PC that will only do a portion of the graphical things a PC equipped with
the top-of-the-range graphics controller can do.
However, it is also important to note that
a regular ATX PC (see 'PC Cases' below) can come with this cut-down graphics
component. Once again, you will most likely see this on budget PCs. The
quickest way to know is to ask the retailer if it has a separate graphics
controller or one integrated on the motherboard.
Which graphic chipset?
Although a large number of manufacturers
build graphics cards for PCs, nearly all of them use components from one
of two major developers of graphics card chips: NVIDIA and ATI. Cards based
on identical graphics chips will be nearly indistinguishable in terms of
performance. Matrox is another well-known brand used by video, 2D and 3D
graphics professionals. A new player, XGI, is also gaining popularity amongst
gamers.
NVIDIA produces graphics controller chips
with the GeForce brand. These are divided up into graphics controllers for
the budget, mainstream or the higher-end/gaming enthusiasts markets. The
latest range of GeForce graphics chips is the 6xxx series, which is now
available in a 6800 version for enthusiasts, or in a 6600 version for mainstream
systems. There's also a range of chips in the 6200 series for the budget-conscious.
Although the grades of graphics controllers
vary, it is quite normal to find features such as TV-out or S-Video on mainstream
controllers, without having to pay more for the high-end controllers. For
example, consumers can pick up an AGP based 6600 graphics controller with
TV out and a DVI port for a little over $200. In comparison, the top of
the range PCIe based 6800 controller will set you back around $650 or $520
for an AGP model. The lower-end chips, however, will run slower and may
not have the cooling or heatsink features which have been incorporated into
the higher-end controllers.
The current range of ATI graphics chips are
branded under the Radeon name. Common Radeon chips include the X600 and
X700, the X300 for the budget buyer and higher-end users can keep an eye
out for chips based on the X850. Prices may vary from $100 for the X300
Radeon to between $160 and $350 for the X600 and X700. The Radeon X850 is
bit more expensive with prices close to the $800 mark so it's best to have
an idea of just how demanding your system requirements are before deciding
on the more expensive option.
Which interfaces do I look out for?
There are two kinds of interfaces in the
motherboard used to connect graphics cards: AGP and PCIe. Whatever graphics
card you buy, it must match the slot in the motherboard.
AGP
The AGP bus is a dedicated graphics connection
used only by an AGP graphics controller. AGP works in various modes. Not
all motherboards support all modes.
AGP 1X mode (which has a speed of 66MHz and
data transfer of 264MBps) is twice as fast as that of PCI (33MHz; 132MBps).
AGP 2X mode (133MHz; 528MBps) is four times faster than PCI.
AGP 4X (266MHz; 1.02GBps).
AGP 8X (533MHz; 2.1GGBps).
Although the capacity of the AGP port will be determined by the main board,
it is worth pointing out that graphics cards support certain AGP standards.
This means that if you purchase a graphics cards separately to your system,
you will need to check the main board is equipped to handle the AGP mode
the graphics card works at.
PCI Express
PCI Express or PCIe was ratified in late
2002 to overcome the limitations of AGP. The new interface has a higher
bandwidth throughput, lower pin count and lower latency, making it overall
the superior choice for graphics. PCIe types can be broken down into four
different modes:
PCIe 1X mode (500MB/s) uses a single data
lane - both directions
PCIe 4x mode (1000MB/s) uses a double data lane - both directions
PCIe 8X mode (4000MB/s) uses a quadruple data lane - both directions.
PCIe 16X mode (8000MB/s) uses 4000MB/s per directions.
Nearly all graphics cards are of the PCIe 16X variety.
A lot of the latest release motherboards
feature PCIe slots and are physically incompatible with AGP cards. If you
are looking to upgrade to PCIe for improved graphics, don't go and sell
your soul just yet. A lot of the games still perform exceptionally well
with an AGP based card but if you're after some serious pixel pushing power,
PCIe may be worth investigating.
What is RAMDAC
You may come across the term RAMDAC in your
shopping. This is an acronym for Random Access Memory Digital-to-Analog
Converter. RAMDAC is a chip on graphics controller cards and its role is
to convert digitally encoded images into analog signals that can be displayed
by a monitor.
RAMDAC speed is a frequency at which the
RAMDAC processes the pixels and sends the video signals to the monitor via
the VGA connector. Speeds to look out for include a range from 270MHz up
to 360MHz. The higher your screen resolution, the higher the RAMDAC speed.
Which memory?
Video cards also contain onboard RAM, which
is used as a working space for the graphics operations.
The two graphics memory types you are likely
to encounter Single Data Rate (SDRAM) and Double Data Rate (DDRAM) memory.
Some of the newer cards also feature DDR-II or graphics DDR (GDDR).
A powerful graphics card will have 256Mb
of memory. Low-end cards normally have less RAM, usually of the DDR variety.
Hard drive
The hard drive on your PC is a storage device,
sort of like a digital briefcase where you keep all your important data.
It works by rapidly recording data with magnetic pulses on spinning metal
platters. The more quickly a drive spins, the quicker you can access and
transfer data.
Hard drives come in a number of sizes, but
3.5in is by the far the most common type for PC computers. Most computer
cases are designed to fit 3.5in drives.
The drive contains a motor that spins the
platters at speeds from 5,400 to 15,000 revolutions per minute (RPM). The
more quickly the drive spins, the more quickly you can read and store data.
Aim for a hard drive with a rotational speed
of 7200rpm over the older 5400rpm models. This will offer the best price/performance
balance.
What sizes do hard drives come in?
The minimum size your hard drive will come
in these days has risen significantly over the past 12 months, and consumers
should be able to find a sub-$1000 desktop PC with between 60GB and 200GB
of hard disk drive space. Drives with up to 500GB storage are currently
available, although you pay a significant premium for hard disks at the
top-end of the capacity spectrum. If you plan on storing large amounts of
data on your hard drive, such as digital images or multimedia files, then
the bigger the hard drive, the better.
As an example, we've used an 80GB hard drive
to illustrate the amount of storage space you'll need to house the following
files:
Depending on various quality and file format
settings used, one minute of near CD-quality music will use around about
1MB of memory. This means that a 5GB player could hold roughly 1000 five-minute
songs. Therefore 4000 songs in MP3 format: 20GB
3 PC games (such as Unreal Tournament II, at 3GB each): 9GB
2 hours of DV footage: 25.60GB
4 hours of recorded TV shows: 4GB
Windows XP: 1.5GB
2 years of stored Outlook e-mail messages for a heavy user: 4GB
11 applications, including Office XP Professional, Norton AntiVirus and
Adobe Photoshop: 1.88GB
1500 JPEG photos (1600x1200 each): 1.41GB
Hundreds of Excel spreadsheets, Word documents and Acrobat files: 1.08GB
FREE SPACE REMAINING: 11.55GB
What are the hard drive interfaces?
The drive interface is the "language"
a drive uses to communicate with a PC. The two main types of PC hard drive
interfaces are the ATA (Advanced Technology Attachment), also known as the
IDE interface, and SATA. SCSI (pronounced "skuzzy") is also available,
but less common.
The ATA and SCSI interfaces have evolved
to include many sub-types, which may or may not be backwards compatible.
SCSI disk drives are expensive, require expensive controller cards and typically
are only used on high-end workstations and servers. Virtually every PC motherboard
has a built-in IDE hard disk controller, which has two connectors called
a Primary and Secondary channel. Each channel can support one or two IDE
drives, making a total of four possible drives. These could include hard
disks, CD/DVD drives, CD writers, or a Zip drive.
The original ATA interface supported a maximum
transfer rate of 8.3MBps. The last three evolutions allow up to 33, 66,100
or 133MBps to be transferred. Today, these numbers are often prefaced with
the word Ultra-DMA or UDMA (ultra direct memory access). Ultra-DMA is also
known as Ultra-ATA or EIDE, and typically will be advertised as Ultra ATA/33,
UltraATA/66, Ultra ATA/100 and now UltraATA/133.
Serial ATA
More recent and more advanced than IDE, serial
ATA, or SATA, was designed to replace parallel ATA (IDE). Users will benefit
from SATA by being able to easily upgrade their storage devices, while configuration
of SATA devices will be much simpler as jumper and settings are no longer
needed. SATA hard disk drives will work with current operating systems and
are software compatible with parallel ATA. Many existing motherboards support
both SATA and PATA. Older motherboards may only support IDE.
The biggest benefit of SATA is its increased
data transfer rates. While the fastest performing parallel ATA drives offer
data transfer speeds of 133MHz, SATA operates with a data transfer speed
of 150MHz. SATA drives also take up less room within the PC case due to
smaller cabling (making them great for use within compact systems).
Although prices for SATA drives were initially
higher than parallel ATA drives, there is now little difference in price
between the two technologies.
PC case
A good case can simplify the task of upgrading or servicing components -
as well as making your office environment that much more pleasant. A well-designed
case will offer tool-less access to the interior, will have hard drives
mounted on easy slide-out trays, and use colour-coded cables for internal
and external parts.
Since motherboards come in different shapes
and sizes, commonly known as a form factor, so do case designs.
The most common form factor is ATX. The ATX
specification not only dictates where the connectors on the back of the
motherboard should be (to line up with the holes in the case), but also
encompasses details such as the power supply connector. There are variations
on form factors -- for example, MicroATX takes the basic ATX specification,
but has fewer expansion slots to allow for smaller cases. Other motherboard
formats exist. AT was the de facto standard before ATX, and NLX is used
to create slimline PCs. A new size to emerge and designed to replace the
ATX standard is BTX. Intel was the driving force behind this new form factor
and features some radical design changes to increase cooling. Similar to
the ATX variations, there are also different form factors for the BTX range
such as picoBTX and microBTX.
Farming attachments
External connectors for sound as well as
serial, parallel and USB (universal serial bus) ports are now attached directly
to most ATX motherboards, which makes them far easier to install than did
the previous AT form factor (where most of the connectors attached to the
motherboard via cables).
Monitors
When PC manufacturers want to shave the dollars
off the price of a PC, the monitor is often the first area they address.
Customers generally choose a system based on hardware specifications such
as processor speed and graphics card, paying little attention to the monitor
other than to note its size. This is a shortsighted approach. Since you
interact with your screen more than any other part of your computer, you
will soon regret any decision to opt for a poor quality display. Monitor
technology does not move on as quickly as that of other PC components, so
the screen is unlikely to become obsolete.
There are two main monitor types that you
will come across when purchasing your PC, a cathode ray tube (CRT) or a
liquid crystal display (LCD). They not only differ greatly in size and features
but also in aesthetics. A CRT monitor is an analog display that produces
images by illuminating phosphors with an electron beam. CRT monitors of
late are being overtaken in the market by the LCDs.
What sizes do CRT monitors come in?
The two common sizes are 17in and 19in. People
wanting that extra viewing space can opt for the larger 21in or even 23in
screen. The most popular size is 17in and is suitable for most PC users,
given that it is the entry-level size. Older monitors, such as the 15in
variety, are incapable of taking advantage of the resolutions supplied by
even the most basic of the modern graphics controllers. If you choose a
17in monitor, you should make sure it supports a resolution of at least
1280x1024. Many manufacturers tout higher resolutions of up to 1600x1200,
but these are not particularly usable on a 17in screen and users are often
happier at a resolution of 1024x768. A larger 19in monitor is usable at
higher resolutions, so make sure your screen supports a resolution of 1600x1200.
Resolution?
The resolution of the monitor - which also
acts as a gauge for the amount of detail a display offers - comes from the
number of pixels (short for "picture elements") and lines. For
example, in a CRT monitor with a 1024x768 resolution, the beam lights up
1024 pixels as it passes horizontally from left to right. When it reaches
the edge of the screen, it stops and moves down to the next line. The beam
repeats this process until it has passed over the 768 lines of pixels on
the screen. When the beam reaches the bottom, it returns to the top and
begins again. A monitor with a 75Hz refresh rate completes this round-trip
75 times per second. However, 85Hz is ideal as it reduces the flickering
you get from slow refreshing monitors. Most resolutions will provide a flicker-free
picture when viewed at 75Hz and above.
What are flat panel displays?
The technology used in flat-panel displays
is quite complex. A liquid crystal solution is held between two sheets of
polarising material. An electric current is then passed through the liquid,
which makes the crystals align and act as shutters, either allowing light
to pass through or blocking it. TFT (thin film transistor) is the technology
used in conjunction with LCD to generate colours for flat-panel displays.
Flat-panel displays are slender and stylish
and are becoming more affordable as new technologies emerge. For example,
a basic 17in CRT costs around $200- $300, while a basic 17in LCD flat-panel
monitor will set you back around $320 to $500. Some LCD models that cost
that little bit extra may even come with integrated speakers, microphone/audio
jacks, USB ports, TV Tuners and pivot functions that enable you to turn
the whole display from a landscape aspect to portrait. Typically, flat-panel
monitors come in sizes of 15in, 17in, 18in, 19in and 21in. The 15in models
are slowly being phased out; 17in is now the entry-level size.
Response times
You may have seen a reference in LCD monitor
specifications to a term called response time and wondered what it was all
about. Response times refer to the amount of time it takes for the crystals
in the panel to move from an on to off state.
With a higher a response time, the greater
the blurring effect on bright moving images on black backgrounds. The lower
the response time, the less of a blurring effect there will be on the screen.
Gamers and graphics professionals tended to shy away from LCDs for this
reason alone but as of late, monitor manufacturers are releasing models
with response times as low as 8 or 4 milliseconds. This can be a misleading
statistic though and gives only a vague idea of the screen quality; be sure
to do your homework when selecting the right monitor for you.
What is DVI?
Most CRT monitors are analog, meaning that
your graphics card has to convert digital data into an analog signal that
can then be used by the monitor. Flat-panels are digital, so this analog
signal then has to be converted back to a digital signal within the LCD
monitor. This can cause setup problems and screen jitter. DVI (Digital Visual
Interface) aims to overcome this problem by taking a digital signal straight
from graphics card to monitor, ensuring that image quality is always clear
and accurate.
Reasons for buying a flat-panel monitor
If you've got the cash to spend, the most
appealing reason for buying a flat-panel monitor is space. You would be
surprised how much desktop real estate is freed up by replacing a CRT with
an LCD. Most models even feature brackets at the rear of the display to
mount on a wall. They also use less electricity, emit less heat and radiation
and weigh much less than CRT monitors. LCD screens also have better screen
geometry. Screen geometry means that no matter where an image on your screen
lies, it will look the same. In CRT monitors for example, when you view
an image at the edge of the screen it can look a little distorted (for example,
it may appear to be a little curved) compared to that same image sitting
in the middle of the screen.
Reasons for sticking with a CRT monitor
LCD TFT devices offer excellent picture quality,
eliminating some of the traditional image problems of CRTs, such as light
refraction and geometric distortion. They also use less power and produce
no radiation. But all these goodies come at a cost. CRT monitors are cheaper.
Another advantage is that the viewable angle of the CRT monitor is much
better than that of an LCD. TFT displays have slowly made in-roads on this
con though and some of the latest models exhibit viewing angles on par with
CRTs.
To illustrate, if you stand in front of your
CRT monitor (90?) and start moving either left or right (even up or down)
of it to being parallel with the screen, the image that you see on the screen
will always be the same, regardless of the viewing angle. Do the same thing
with an LCD screen, and as you get closer to the axis of the display on
some of the cheaper models, you will find the image just drops out, giving
you a black screen.
Sound cards
At its most basic level, a sound card (also referred to as an audio card)
is an expansion card that the PC utilises to read and play sound files.
A sound card has four main functions: as a synthesiser (generating sounds),
as a Musical Instrument Digital Interface or MIDI interface (the standard
that allows musicians to hook up instruments to sound cards), as an analog-to-digital
converter (used, for example, in recording sounds from a turntable), and
as a digital-to-analog converter (to reproduce sound for a speaker, for
example).
Almost all PCs are configured with sound
cards as standard issue, but in some cases these will be two-channel stereo
cards that are good for playback of two-channel CD music, MP3s, low-level
PC gaming and not much else. Lately, though, some motherboards have shipped
with on-board eight-channel audio, providing digital 7.1 sound reproduction
capability.
When buying a PC, the sound card you purchase
will determine the quality of the sound you wish to output. If you are going
to be producing music on your PC, then a serious sound card with plenty
of connectivity (for the MIDI interface), low latency and ASIO 2.0 driver
support is required, which could cost around $450 and above. Some high-end
sound cards may even bundle an external breakout box which provide extra
connectivity and easy access to audio jacks. If, however, you want something
that can just produce decent music output and can be used for gaming, then
a card with fewer features and priced between $55 and $150 will probably
do the job.
Sound card interfaces
Sound cards connect to your computer through
the PCI slot. A PCI slot is a type of interconnection system, which allows
peripheral devices such as sound cards, modems or TV tuner cards to communicate
with the computer's processor.
Dolby Digital
The latest sound cards include Dolby Digital
5.1 or 7.1 processing, which will give you true digital surround if you
invest in a good PC surround speaker set or hook up your computer to your
home theatre system. Be sure to get surround speakers that match your surround
sound card in terms of channels (5.1, 6.1, etc.) and connections.
Speaker systems
A new sound card can be a waste unless you
also upgrade your speakers. Most off-the-shelf PCs come with cheap-looking
speakers that produce tinny, AM radio-like sound. Figure on spending $100
to $200 for a good-quality set of speakers; the higher-priced systems include
rear speakers and even a front and rear centre channel speaker for true
3D sound (Take note: a subwoofer represents the '.1' in 5.1, 2.1 or 4.1
speaker systems).
Regardless of which sound card you choose,
note that your card and speakers must have matching digital connections,
and that sometimes the Dolby Digital encoding within both can be handled
differently by various manufacturers. If you plan to buy a card from one
vendor and speakers from another, check with the vendors to be sure that
their products can make sweet music together.
Media centre PCs
Introduced in the US back in 2002 and launched
here in Australia late last year, Microsoft unveiled a new operating system
titled Windows XP Media Center Edition 2005. MCE is basically a version
of Windows XP Home but using an interface that allows PCs to become more
effective home entertainment systems, complete with a TV/Radio tuner card
and remote control. You can record and pause live TV (time shifting), watch
DVDs or view video and photo files.
Overseas, the uptake of MCE has been quite
positive but we're yet to see the same type of response here in Australia.
One of the contributing factors for MCEs slow rise is the omission of Electronic
Program Guide (EPG); a cool feature that enables digital television users
to search, filter and customize program listings and even control access
to content.
Microsoft's new operating system (Vista),
due to be released roughly at the end of 2006, will provide a new interface
design, which will also allow for a greater media experience.
Questions to ask the retailer
1. Do you provide delivery? Is it free?
You would be surprised what responses you
will get. Ask this before you hand over money and thus ensure you don't
pay extra.
2. Do you extend the warranty?
The longer the warranty period, the less
chance you will need to incur additional costs should anything go wrong.
3. Do you provide after-hours support?
PCs give you grief at all hours of the day.
Not all retailers supply such a service.
4. Is the PC in stock?
A $2000 PC today may well be worth $1500
in two months' time. There is no point 'buying' a PC and then having to
wait months for it to arrive at which time you could buy it for less.
5. What operating system and software are
included?
Most desktop PCs and notebooks come with
some flavour of Windows, with Windows XP Home or Professional now being
the standard. Older, sell-out stock from your local retailer may still come
with Windows 2000. You'll be hard pressed to find Linux or other alternative
operating systems pre-installed on any desktop or notebook PC.
You may pick up some real bargains in terms
of bundled software, including utilities, productivity software (such as
Microsoft Works or an office suite) and occasionally games or multimedia
titles. Finding the right retailer
Thinking of going the local route? Word-of-mouth advice is a good place
to start. Follow these tips to help you home in on the best store.
Do: visit recommended stores in person -
just to chat. Ask to meet the owner and trust your gut feelings about how
responsive the store will be.
Do: follow the 5/25 rule if you can: choose
a store that has been in business for at least five years and is located
no more than 25km from your home or office.
Do: pursue multiple options. Compare prices,
warranties and support hours.
Do: show the sale staff that you've done
your homework on parts makers. If the store doesn't stock the brand you
want, ask whether staff can hunt the item down.
Don't: choose a store that pressures you
to buy 'today' because of a massive sale.
Don't: purchase from a store where the sales
representatives try to talk over your head using technical jargon, or make
you feel like you're not worth their time.
Don't: be impressed by 'paper' technicians.
Industry certification should not sell you on a store's tech support staff.
Instead, ask how long techs have served customers; the more years, the better.
6. How can I tell if the software is legal?
One of the biggest concerns with bundled
software is whether you're getting the genuine article. To help those wanting
to know more about how to identify pirated software, Microsoft has established
a licensing section on its web site dedicated to protecting users from pirated
copies of its software products.
According to the Microsoft site, the best
ways for you to confirm that the software you have been given with your
PC or notebook is authentic software from Microsoft is to first check your
end user license agreement. If you have purchased your PC from a retail
outlet and have been given the software with it, check the Microsoft license
pack and look for the certificate of authenticity (COA) on the box.
Alternatively, if the software has already
been installed on the PC, look for the COA which accompanied the product.
For OEM products, the COA is either on a separate page or affixed as a label
to the PC chassis.
Open license customers can view their electronic
purchase history via the Microsoft web site. This site also maintains a
free software inventory analyser, which can tell you what Microsoft products
you have loaded on your PC.
For more information on these, check out
the Microsoft web site.
Besides the operating system, PC or notebook
buyers may also receive a range of other software products either bundled
with or pre-installed on their system, including reference, business or
education programs.
For more general information on pirated software,
the BSAA has compiled consumer guides on what to look out for when purchasing
PC software. These not only cover new software, but also look at purchasing
new or second-hand software online. More information is available on their
web site.
The site also provides links to piracy statements
from a variety of software providers, such as Macromedia, Symantec, Autodesk
and Adobe. All such sites advise users to purchase their PC and related
software from a reputable reseller, and to check that all software comes
with authentic packaging and a license agreement. Even if the software has
already been pre-installed on your PC or notebook, the reseller should still
provide you with a software license agreement. You should also receive the
original software discs and manuals for all of the software pre-installed.
Users can seek further information on anti-piracy
laws and report suspected pirated software to the Software and Information
Industry Association (SIIA). The trade organisation has over 800 member
companies from the software and Internet industry worldwide.
Sourced from www.pcworld.idg.com.au
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