The HyperTransport Technology Consortium released a new specification aimed at increasing the efficiency of packet-based chip-to-chip traffic. The new DirectPacket HyperTransport 1.1 specification provides four new capabilities: native packet handling for efficient transport of user packets through board-level systems, a robust retry protocol for high reliability server and communications systems, peer-to-peer routing for direct connection between I/O devices, and three new sets of Virtual Channels including 16 channels optimized for streaming traffic.
The new specification could be used in servers, storage systems and network equipment when integrating board-level systems to high speed, packet-based I/O technologies. The protocol uses 8 bytes of overhead for Write operations and 12 bytes of overhead for Read operations. In addition, the new peer-to-peer routing allows direct communication between HyperTransport-enabled devices without routing traffic through the attached host when PCI ordering is not required by the application.
HyperTransport is a universal chip-to-chip I/O connectivity technology that provides 12.8 Gigabyte/second bandwidth, frequency and width scalability. It also provides software compatibility with the legacy Peripheral Component Interconnect (PCI) and PCI-X I/O technologies.
http://www.hypertransport.org
