14 Facts About PCI Express

1.

PCI Express, officially abbreviated as PCIe or PCI-e, is a high-speed serial computer expansion bus standard, designed to replace the older PCI, PCI-X and AGP bus standards.

FactSnippet No. 1,446,781
2.

In contrast, PCI Express is based on point-to-point topology, with separate serial links connecting every device to the root complex .

FactSnippet No. 1,446,782
3.

Furthermore, the older PCI Express clocking scheme limits the bus clock to the slowest peripheral on the bus .

FactSnippet No. 1,446,783
4.

The PCI Express standard defines link widths of x1, x2, x4, x8 and x16.

FactSnippet No. 1,446,784
5.

The PCI Express bus has the potential to perform better than the PCI-X bus in cases where multiple devices are transferring data simultaneously, or if communication with the PCI Express peripheral is bidirectional.

FactSnippet No. 1,446,785
6.

PCI Express is one example of the general trend toward replacing parallel buses with serial interconnects; other examples include Serial ATA, USB, Serial Attached SCSI, FireWire, and RapidIO.

FactSnippet No. 1,446,786
7.

PCI Express Mini Card, based on PCI Express, is a replacement for the Mini PCI form factor.

FactSnippet No. 1,446,787
8.

An example of the uses of Cabled PCI Express is a metal enclosure, containing a number of PCIe slots and PCIe-to-ePCIe adapter circuitry.

FactSnippet No. 1,446,788
9.

OCuLink is an extension for the "cable version of PCI Express", acting as a competitor to version 3 of the Thunderbolt interface.

FactSnippet No. 1,446,789
10.

PCI Express is a layered protocol, consisting of a transaction layer, a data link layer, and a physical layer.

FactSnippet No. 1,446,790
11.

PCI Express requires all receivers to issue a minimum number of credits, to guarantee a link allows sending PCIConfig TLPs and message TLPs.

FactSnippet No. 1,446,791
12.

PCI Express operates in consumer, server, and industrial applications, as a motherboard-level interconnect, a passive backplane interconnect and as an expansion card interface for add-in boards.

FactSnippet No. 1,446,792
13.

For example, making the system hot-pluggable, as with Infiniband but not PCI Express, requires that software track network topology changes.

FactSnippet No. 1,446,793
14.

PCI Express falls somewhere in the middle, targeted by design as a system interconnect rather than a device interconnect or routed network protocol.

FactSnippet No. 1,446,794