What hardware and software is needed to support PCI Express 3.0? Are previous peripheral devices compatible with PCIe 3.0 slots?
Fully deploying servers with PCIe 3.0 will require a motherboard that supports one or more PCIe 3.0 slots along with PCIe 3.0 peripheral devices. Numerous server system boards are already available, including the Intel S2600WP or S4600LT2, the ASUS P8C WS ATX and the Tyan S5512GM4NR server motherboards. Next-generation servers for future tech refreshes will undoubtedly include PCIe 3.0 slots by default.
Firmware support will usually be native to the new motherboard, and driver support is available through the operating system, but it will be important to verify OS support before committing to PCIe 3.0 deployment.
One additional consideration for any PCIe deployment is backward compatibility between motherboards and devices. For example, PCIe 2.0 slots are backward compatible with PCIe 1.0 cards, and PCIe 1.0 slots are typically compatible with PCIe 2.0 devices. The PCI-SIG has also announced that PCIe 3.0 would be backward compatible with earlier PCIe implementations. However, there is little practical benefit to backward compatibility.
For example, a business that makes the investment needed to upgrade servers or server motherboards to support PCIe 3.0 slots will not continue to use PCIe 2.0 devices in those slots. Even when the configuration functions, performance will be limited to the older device. If you must rely on backward compatibility -- such as using an older network interface card (NIC) until a newly ordered PCIe 3.0 NIC arrives -- be sure to test the platform carefully before placing it into production.
This was first published in April 2013