Introduction
The most important component of a motherboard is its chipset.
The chipset contains the core logic that runs the show. It
is generally made up of two components; the Northbridge which
controls the buses (i.e. PCI and memory) and the Southbridge
which controls the peripherals (i.e. serial and parallel ports).
Intel, VIA, Ali and AMD produce the majority of chipsets today.
Motherboard manufacturers like Asus, Abit, Tyan, etc, build
their boards around the chipset. Only a few years back, the
chipset choices were very limited. However, choosing a motherboard
today can be a very confusing exercise. First you have to
decide which processor you are going to use and then which
chipset you want to support that CPU. Only then can you decide
on a motherboard. If you have existing memory that you want
to transfer to the new board, that presents another wrinkle.
To understand how we arrived at where we are today, a little
history lesson is in order.
A little history
It would be too lengthy an article to discuss all of the chipset
choices or features here. Instead, this a brief synopsis of
the major players during each evolutionary step in chipset
technology.
When Intel first introduced the Pentium processor in 1992,
there was only one choice of chipset - the 430FX. That was
followed by the 430VX and 430HX chipsets. The 430HX was designed
for the power user with the ability to cache more than 64MB
of RAM and dual processor support. The 430VX chipset in return
did offer support for SDRAM. The 430TX chipset came next with
its Ultra 33 support and was supposed to be the replacement
for both the VX and the HX chipsets. However, the TX didn't
support caching more than 64MB of RAM or dual processors.
So for a time, the TX and HX chipsets coexisted. The Pentium
Pro, designed for the server market, was released during the
later days of the Pentium processor and had it's own chipset,
the 440FX.
The launch of the Pentium II processor, in 1997, saw the introduction
of the 440LX chipset. It's claim to fame, other than Pentium
2 support, was the inclusion of an AGP 1X slot for a new breed
of graphics adapters. This however, was when things began
to get confusing. AMD, after being relegated to low-end computer
hell, introduced the K6. Since they didn't have licensing
rights for the Pentium II's Slot 1, they developed the K6
for Socket 7 motherboards. This meant that they could continue
to use the 430TX chipset. VIA, Ali and SiS began making their
own Socket 7 chipsets, dubbed Super Socket 7. This allowed
them to exceed the speed limit of 233MHz imposed by the TX
chipset. AMD followed with the very successful K6-2 and K6-3
processors.
The 440BX chipset quickly replaced the 440LX chipset. It exchanged
the AGP 1X slot with the faster AGP 2X slot. Though the confusion
may have started earlier, it hit full force when AMD decided
to develop the Socket A interface for their upcoming K7 processor
(the Athlon). This required them to develop their own chipset.
They licensed Alpha's EV6 bus technology with its 200MHz Front
Side Bus (FBS). This "fork in the road" has led us to the
state of chaos we are in today. VIA, not content to sit on
the sidelines, has developed chipsets as well for both Intel
(Pentium 2/3) and AMD (Athlon) processors. Just when it seemed
we could get a handle on the whole thing, Intel decided to
support a new memory technology - Rambus. As expected, this
required a new chipset, the i820 and it's various siblings.
