Trenton’s new JXT6966 system host board supports PCI Express Gen 2.0. As there are a number great questions and answers out on the PCISIG website regarding PCIe 2.0 it made sense to publish some of those comments here on the Trenton blog and share with our readers.
Q: What are the benefits of PCIe 2.0 and what business opportunities does it bring to market?
A: While doubling the bit rate can satisfy high-bandwidth applications, faster signaling has the added advantage of allowing various interconnect links to save cost by adopting a narrow configuration. For example, a PCI Express 1.1 x8 link (8 lanes) yields a total aggregate bandwidth of 4GBytes/s, which is the same bandwidth obtained from a PCI Express 2.0 x4 link (4 lanes) that adopts the 5GT/s signaling technology.
This can result in significant platform implementation cost savings while maintaining an identical level of performance. Backward compatibility is also retained as existing 2.5 GT/S adapters can plug into a 5.0 GT/S slot and will run at the slower rate. Conversely, new PCIe 2.0 adapters running at 5.0 GT/S can plug into existing PCIe slots and run at the slower rate of 2.5 GT/S.
Q: Then PCIe 2.0 must be backward compatible with PCIe 1.1 and 1.0?
A: Yes. The PCIe Base 2.0 specification supports both the 2.5GT/s and 5GT/s signaling technologies, so a device designed to the PCIe Base 2.0 specification may support 2.5GT/s, 5GT/s or both. However, a device designed to operate specifically at 5GT/s must also support 2.5GT/s signaling. The PCIe Base specification covers chip-to-chip topologies on the system board.
For I/O extensibility across PCIe connectors, the Card Electromechanical (CEM) and ExpressModuleTM specifications will also need to be updated, but this work will not impact mechanical compatibility of the slots, cards or modules. The PCI-SIG is defining a PCIe CEM 2.0 specification which has been released to members for review at v0.5. There are currently no plans to adapt the PCIe Mini CEM specification for the faster bit rate as the market need has not yet materialized.
Q: What are the initial target applications for PCIe 2.0?
A: The same set of core applications, high-performance graphics, enterprise-class storage and high-speed networking that benefited from the introduction of PCIe 1.0 architecture are expected to lead the charge for adoption of PCIe 2.0.
PCI Express 2.0 technology represents a significant improvement in system performance compared to PCIe 1.0 products and will be most appreciated when deploying Government & Defense, Medical and Video Processing applications. A fully integrated rackmount computer system which incorporates one of Trenton’s PICMG 1.3 backplanes, will take advantage of PCI Express 2.0 bandwidth in support of video wall controllers, military computer systems and robust GPU computing platforms such as the TCS4501 rackmount computer.
Trenton TCS4501 Rackmount Computer
