Conclusion - HP BL680c - ProLiant - G5 Introduction Manual

In order to provide maximum flexibility during the continuing transition to PCI Express, several of the
current ProLiant systems have been designed with replaceable I/O daughterboards. Depending on
their mechanical characteristics, these may be referred to as riser, mezzanine, or sub-I/O boards, but
they are all designed to allow part of the I/O subsystem for a ProLiant server to be configured in one
of three distinct ways:
• As PCI-X slots to provide backwards compatibility
• As a small number of high-bandwidth PCIe slots
• As a larger number of lower bandwidth PCIe slots
This design approach provides maximum flexibility by allowing customization of the I/O
configuration of the server to meet each customer's specific requirements.
Customers who require peripheral bandwidth in excess of 1 GB/s will likely find those peripherals
implemented with PCI Express technology. It is expected that most device manufacturers will use PCI
Express technology for higher bandwidth peripheral devices such as 10-Gb Ethernet and 10-Gb Fibre
Channel. For peripherals that require bandwidth less than 1 GB/s, PCI and PCI-X will remain viable
technologies and continue to provide backward compatibility. It is anticipated that device vendors will
manufacture peripherals with bandwidth requirements in the 1 GB/s range in two versions, providing
options for customers to choose either PCI Express or PCI-X technology
HP will continue to deliver newer PCI Express technology to the market, including PCIe 2.0 and higher
powered PCIe slots. In addition, HP is also committed to delivering the latest innovations in local I/O
such as the emerging I/O virtualization technologies.

Conclusion

As customer requirements for higher bandwidth in the I/O subsystem continue to increase, the
industry transition to PCI Express technology to provide that bandwidth is well underway. PCI Express
and PCI-X technology will coexist in ProLiant servers, giving customers flexibility in their choice of
technology and providing a path for transition to higher bandwidth peripherals.
HP has been a leader in the development and implementation of industry-standard I/O technology
and continues to be an active member of the PCI Special Interest Group. HP is committed to delivering
industry leading products that meet customer requirements for flexibility, performance, and investment
protection. HP demonstrates its commitment by providing an ongoing transition path to PCI Express
technology as well as support for other emerging server I/O technologies such as I/O virtualization.
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