Backward Compatibility; Form Factors - HP ProLiant DL985 Introduction Manual

Figure 5 illustrates the bandwidths of PCI, PCI-X, and PCI Express, which will provide sufficient I/O
bandwidth migration for server I/O growth requirements. PCI Express bandwidth is shown using the
sum of the receive and transmit bandwidths.
Figure 5. I/O bandwidth of PCI, PCI-X, and PCI Express
9000
8000
7000
6000
5000
4000
3000
2000
1GbE
1000
1GbFC
1394b
0
PCI PCI
32/33 64/33

Backward compatibility

PCI Express is compatible with PCI at the software layers (operating system, applications, and
drivers). New software is required to take advantage of new and extended PCI Express architecture
features. The PCI Express configuration uses standard PCI plug and play mechanisms and PCI Hot
Plug mechanisms. PCI Express is not compatible with PCI at the board or connector level.

Form factors

The PCI Express specification includes a range of form factors and connector sizes. Connector sizes
include the following:
• x1 connector for desktop I/O
• x4 and x8 connectors for server I/O
• x16 connector for desktop graphics
servers only
Quad U320
Dual U320
1x IB
PCI x1 PCI-X PCI-X
64/66 PCI Exp 100
Integrity
10GbE
10GbFC
x2 PCI-X x4
133 PCI Exp 266 PCI Exp
x8 x16
PCI Exp PCI Exp
6