What Chipsets Do

You have to consider a lot of factors when deciding on a final configuration

for your PC. The processor, amount of memory, video card, hard-disk capacity,

etc, are the foundation of a good configuration. However, the foundation for

these–the motherboard and its chipset–if often ignored.

A chipset is a combination of chips that sit on the motherboard. It’s

responsible for most communication that takes place between different components

on the motherboard; and decides many important features of a motherboard, like

the AGP speed (2x or 4x), peak hard-disk speed (ATA 66/100), memory type (RDRAM

or SDRAM) and size. Chipsets differ in the features and functionality that they

can offer to a motherboard, and consequently the entire system. Therefore,

knowing about various chipsets and how they differ in their functionality can

help you decide the best motherboard for your needs.

In the old days, the chipset was usually a given. If you were going to buy an

Intel processor, you had little choice but to go in for an Intel chipset.

However, things have changed. While the contenders in the chipset market–Intel,

AMD, VIA, Ali, and SiS–remain more or less the same, the choices offered by

them have increased.

In this article, we’ve compiled a list of the most commonly available

chipsets for the PC platform. Please refer to it as we take you through the

various aspects that they control. Since a majority of the desktop market uses

chipsets based on Intel or AMD processors, we’ll take a look at them in

detail.

CPU interface

The type of packaging–that is, the casing that houses the

CPU circuitry–done for microprocessors has been under constant development.

Due to this, the type of interface a CPU uses to connect to a motherboard, which

is identified by a chipset, also changes. Fortunately, the choice of interfaces

available here is restricted. Most new AMD processors like Thunderbird and Duron

use the Socket A interface, while Intel prefers Socket 370 for Celeron and PIII

processors. However, chipsets supporting older interfaces like Socket 7, and

Slot 1 are still available. Socket 7 was used for the earlier Pentium, Cyrix,

and AMD K6 series of processors.

Chipsets'

Capabilities

Sound and video support

Some motherboards, like the i810, come with integrated sound

and video. So, you don’t have to spend extra for these components. Thus,

motherboards based on the i810 and similar chipsets are a hit in the entry-level

segment and on the corporate desktop. In fact, AMD Duron’s poor market share

vis-à-vis the Celeron is sometimes attributed to the absence of an integrated

chipset for the former.

The flip side of an integrated chipset is that if the sound

and video stop working for some reason, you can’t add others. So, you can’t

upgrade your machine as your needs grow. That’s where the i815E chipset comes

into the picture. This new chipset has options for both onboard and external

video. You can disable the on-board audio and video, and put in your own cards.

The chipset also determines the AGP port, which is normally

used to house the video card. The AGP port decides the amount of data that the

CPU can transfer to the video card in a given time. Most AGP ports today run at

speeds of 2x or 4x. Whereas AGP 2x supports a total bandwidth of 533 MB/sec, AGP

4x doubles this to 1,066 MB/sec. 2x is fine for normal work, but it’s better

to go for a chipset supporting 4x AGP if your needs are likely to increase in

future.

FSB settings

Another critical function governed by chipsets is the Front

Side Bus (FSB) speed. This is the maximum speed at which memory on a motherboard

can run. Three FSB speeds commonly available today are 66 MHz, 100 MHz, and 133

MHz. Also, the CPU speed is a multiple of the FSB speed. This multiple is also

referred to as the clock multiplier for a chip. Till now, 66 MHz FSB was widely

used for Celeron processors. However, even the Celeron has recently become

available on 100 MHz. So maybe it’s goodbye time for 66 MHz FSB. PIII

processors support 100 MHz and 133 MHz, while AMD processors double these bus

speeds to 200 MHz and 266 MHz. It’s again up to the chipset to build support

for higher bus speeds and more multiples so that more CPU speeds can be

incorporated.

Hard-drive controller

When we say that a chipset has an ATA-66 controller, it means

that it can support a peak transfer rate of 66 MB/sec for hard drives. ATA-66

support has been the standard in most motherboards. However, ATA-100 was

recently introduced. To utilize these higher transfer rates, the hard drive you

use must have support for it. You can’t expect an Ultra-ATA 33 drive to sit on

an Ultra-ATA 100 interface and give you peak transfer rates of 100 MB/sec.

Moreover, these transfer rates are theoretical. Hard drives have a lot of other

overhead that prevents them from achieving these.

RAM

Nowadays, not only does RAM run at different speeds, there

are also different kinds of memory. Whereas the most commonly used memory, SDRAM,

is available in 100 MHz and 133 MHz FSB, there’s also a new player, RDRAM, in

the arena. Both these memories are backwards compatible. Thus, you can use a

slower memory even if a higher speed is supported. However, switching between

two different kinds of memory, SDRAM and RDRAM in this case, is not possible.

USB

Chipsets also govern USB support on a motherboard. With USB

fast becoming the de-facto standard for most peripheral devices like keyboards,

mice, printers, scanners, and digital cameras, the more USB ports you have, the

better it is.

Hardware monitoring

Hardware monitoring is a useful feature, though it’s mostly

used by power users for the purpose of overclocking. It can warn you in case

your CPU fan dies all of a sudden, the temperature of your CPU goes too high, or

there’s a problem in the voltage being supplied to the processor. However,

this is more of an accessory than an essential feature.

Chipsets'

Capabilities

Anuj Jain