PCIe 3.0 backwards compatible with PCIe 2.0
PCI Express 3.0 will be backwards-compatible with PCI Express 2.0, Yanes said. Since the connector will remain the same, the only difference should be in the electrical specifications. Note that while PCs will only require one connector, servers will still use two PCIe 3.0 connectors, the same as with PCIe 2.0.
While that’s the plan, it’s not set in stone: the base spec is expeted to be completed in late 2009, while testing is set for a year later, in the second half of 2010. It’s unclear how soon after that products will be released.
The other interesting thing was that the SIG has proposed a standard for I/O virtualization, a sticking point in virtualized environments. Basically, what the SIG proposes will work both under a direct connection as well as a fabric-based structure. Address translation is included.