The PCI Express Data Bus

The personal computer is constantly changing with such component
upgrades for memory,cpu speed and hard drive capacity.And the
video display is no exception.

The video display consist of a Graphics Card, Monitor,and the
Bus.If you're wondering what the heck is a Bus in any video
display,its the data path along which data moves into, out of,
and inside the the computer.

This data is sent from the motherboard and central processing
unit, to the graphics card,travels along the data path or Bus,
to the Monitor where our eyes can see it.The data Bus is partly
responsible for our clear and fast the graphics of our favorite
games are displayed.

It does not matter how fast the CPU chip or graphics card can
send data if the Bus becomes too small and prevents the data
from traveling fast.This causes a bottleneck of data when the
graphics card sends data faster then the Bus can allow it to
travel.

The first Bus was introduced by IBM or International Business
Machines and was called the ISA.The Industry Standard
Architecture Bus was slow and weak since it sent data at just
4MHz.

But it was matched with the CPU chip of that day.The average cpu
speed during this time was around 4.77MHz. This bus came in 1981
and IBM created a faster bus soon after with a 16 bit bus with a
cpu speed of 8 to 10 MHz three years later.

By this time many other computer makers were building Computers
using the IBM design and IBM quickly responded to the
competition by making a proprietary bus called the MCA or Micro
Channel Architecture.

When IBM built proprietary Buses they mean they built hardware
or software, in this case Buses, owned and controlled by a
single individual or organization.

The Bus technology came about in the following order.

1983 IBM introduced the ISA Bus and in 1984 the faster 16 bit
ISA Bus arrived.Then in 1987 the 32 bit MCA Bus showed up.And in
1988 Compaq and other PC makers released the 32 bit EISA or
Extended Industry Standard Architecture bus1993 brought us the
Video Electronics Standards Association or the VESA Bus.This
year also allowed the release of the PCI or Personal Computer
Interconnect Bus.

And in 1996 came the AGP or the Advanced Graphics Port while
1998 brought us the AGP 2.0 and in 2002 came the ,you got it,
the AGP 3.0 data bus.Finally in 2005 Intel and AMD introduced
computers running at speeds of 4Gigabytes or more.At these
speeds the AGP port presented at slowdown for the data.

So the folks at Intel put their heads together and came up with
the PCIe.The Personal Computer Interconnect Express.The bus is
like the PCI but uses a serial port whereas the PCI use parallel
ports.

Parallel ports send data in chumps and Serial ports send data
one at a time.With the PCI bus, each slot share a maximum of
132MB a second and the PCIe allow each slot to have 250
Megabytes a second to send data.

PCIe is intended to be used as a local interconnect only.As it
is based on the existing PCI system, cards, and systems can be
adapted to PCI Express without any change in software.The higher
speeds on PCIe allow it to replace almost all existing buses.

Nearly all high end graphics cards today in 2006 from AIT and
NVIDIA use PCI Express.And Nvidia use the faster data transfer
of PCIe for their SLI or Scalable Link Interface technology.

This technology allow two graphics cards of the same chipset and
model number to be ran at the same time. This greatly boost
performance like you never thought possible. Not to be out done,
ATI came on the scene with their dual GPU system or Graphics
Processing Unit called the Crossfire.

As you can see, the PCI Express bus is faster and if possible,
when purchasing your next computer, be certain it comes with PCI
Express slots.

The AGP data bus was fast compared to the PCI but they are both
fading away.So it is very beneficial to you if you get to know
and understand the PCIe in every detail.

Otis F. Cooper is solely dedicated to boosting the knowledge and confidence of every computer user. Sign up to receive his informative articles every month and learn PC Repair absolutely free.Sign up now at www.ultimatepcrepair.com