The HyperTransport Consortium has announced anew I/O interface for high-performance computing.

HyperTransport is a chip-to-chip interconnect technology that supplies high bandwidth, which in turn increases data throughput. It was developed to fix a problem that emerged: new high-speed devices had become so fast that the speed they passed information across to the central processor exceeded that of the system interconnects: this impacted performance.

Apple currently uses the technology in its Power Mac G5s. In these, it handles communication between the processors, FireWire bridges, hard-drive controllers and Ethernet, for example.

Speedy I/O offers future opportunity

The new I/O - HTX - is described as, "the industry's first HyperTransport technology expansion connector specification". Specifications for internal and external connections for this system are described, including mother- and daughter-board connections, the EATX spec.

The aim is to define a standard HyperTransport expansion interface for use with popular motherboards and add-in cards. In effect it opens the doors for very high-performance add on devices, while the daughtercard mechanical specification is compatible with standard PCI cards for exisiting chassis designs.

HyperTransport ConsortiumTechnical Working Group chairman, Brian Holden, said: "The new HTX connector/daughtercard specification is an important milestone for HyperTransport technology.

"It gives system and subsystem manufacturers a standard way to attach HyperTransport-enabled subsystems to HyperTransport-enabled motherboards. The high-throughput, low-latency HyperTransport link is an integral part of many 64-bit motherboards and a key interprocessor link for multiprocessor systems."

Tech info

The specification defines an 8- or 16-bit HyperTransport interface with an up to 1.6 gigatransfer/second data rate (800 Mhz clock rate). It includes all the defined HyperTransport control signals including a synchronous reference clock. The connector signals include both 12V and 3.3V power signals, a SMBus interface (3.3V), optionally supports JTAG and enables the use of 4-layer motherboards and daughtercards with conventional PCB technology.

The new HTX specification is optionally compatible with the standard Extended ATX (12-x-13-inch) motherboard form factor.