 - PCI Express (PCIe or PCI-E) is a high-speed expansion card format that
connects a computer with its attached peripherals. PCI Express was
developed by Intel Corp. in 2004 to replace the peripheral component
interconnect (PCI) and PCI-X expansion buses, along with the accelerated
graphics port (AGP) graphics card interface. PCI-E allows data center
managers to take advantage of networking technologies like Gigabit Ethernet, RAID and InfiniBand.
PCI Express is a serial interface format, unlike PCI and PCI-X,
which are parallel formats. Every device connected to a motherboard
using PCI-E has its own dedicated point-to-point connection. Each of
these connections is called a "lane" and is controlled by a switch. As a
result of this architecture, connected devices don't have to share
bandwidth passing through a single bus, as they would using PCI. This in
turn enables more scalable performance, lower latency and higher data
transfer rates. Condensing many parallel buses to one serial connection
saves physical space on the back of servers and workstations, crucial
where rack space is at a premium. PCI-E also allows hot plugging and hot
swapping.
PCI-E does not require any changes to software or operating systems, as
the identification of devices attached to a PC is determined by the same
protocol used by PCI. This software compatibility is not, however,
matched by backwards-compatible hardware. PCI-E plugs are either shorter
or longer than wide PCI and AGP connectors. The interface does allow
different sizes of PCI-E cards to be used, as smaller cards can be
plugged into larger slots with no issue. PCI-E's low-voltage I/O also
requires fewer pins than other PCI buses, which minimizes costs given
that fewer wires must be routed on the motherboard.
External PCI Express, in which the interface is housed outside of a PC, was
introduced in 2007. When combined with externally-housed graphic cards,
External PCI-E allows users to drive monitors that would normally be
beyond the capabilities of a given laptop.
| LAST UPDATED: |
28 Mar 2008
|
 |
Read more about PCI Express:
|
|
Do you have something to add to this definition? Let us know.
Send your comments to techterms@whatis.com
|
|
