HyperTransport Technology Consortium, the non-profit industry organization that manages and promotes low-latency HyperTransport technology, announced that is has approved HTX, the industry’s first HyperTransport technology expansion connector specification.

The new HyperTransport EATX mainboard and daughtercard specification defines an interface and form factor specification for an EATX mainboard connector and HyperTransport add-in cards. The EATX mainboard is a popular architecture used in high-performance workstations, servers, embedded systems and storage systems. The new HyperTransport Consortium HTX slot standard is intended to accelerate the deployment of HyperTransport technology in the high-performance systems market by defining a standard HyperTransport expansion interface for use with popular mainboards and add-in cards.

The HyperTransport HTX Mainboard/Daughtercard specification defines an 8- or 16-bit HyperTransport interface with an up to 800MHz clock rate and includes all of 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 mainboards and daughtercards with conventional PCB technology.

The new HTX specification is optionally compatible with the standard Extended ATX (12” x 13”) mainboard form factor. The daughtercard mechanical envelop is compatible with standard PCI cards to fit in existing chassis designs. The HTX components are designed to be used in both riser-based (1U) and pedestal, rack-mount (3U and greater) and proprietary systems. The placement of the connectors are designed to exclude the possibility of accidentally inserting cards built to other known interface specification. The specification defines the mechanical locations of the connectors, pinouts, signaling conventions, mechanical specifications for the 1U riser card and the HyperTransport daughtercard, and layout rules for mainboard, riser, and daughtercard.

It is unclear which add-in cards will be made for HTX slot besides InfiniPath adapter from PathScale.