PCIe 2.0 up and running

PCI Express 2.0 base specification has now been finalised and released

The PCI Express (PCIe) 2.0 base specification has been finalised and released, doubling the interconnect or signaling bit rate from 2.5GT/s to 5GT/s to support high bandwidth applications like graphics, networking and storage. Component manufacturers are expected to start integrating PCIe 2.0 components into new servers and desktop PCs within the year.

The spec was finalised by the PCI special interest group (PCI-SIG) in mid-january and is backwards compatible with the existing 1.1 standard. The key benefit of PCIe 2.0, said PCI-SIG chairman and president Al Yanes, is the faster signaling that delivers up to 16Gbyte/s of bandwidth in a 16 lane link. But vendors designing graphics cards and network adapters may also be able to implement narrower interconnect links for higher performance while reducing cost.

‘It helps to better distribute performance for connections going through a route port to a bridge. Instead of adapter vendors buying eight PCIe 1.1 lanes, they can buy four PCIe 2.0 lanes to achieve the same bandwidth, and support Infiniband and 10GbE and high end applications,’ he said.

New protocol layer improvements allow developers to design devices that can optimise platform performance and power consumption, including dynamic link speed management, link bandwidth alerts that notify users of changes in link speed via software, increased register control for better device management and power limit redefinition that will extend the existing 150w power supply to support 230/300w devices.

‘The typical rule of thumb is that within a year of the spec being released parts start to show up but some manufacturers will jump on faster than others. I expect anyone integrating high-end graphics into servers and workstations will be first to use the increased throughput,’ added Yanes.

The PCIe Base 2.0 specification is available for download.