ATI signs up to support 3GIO

ATI has thrown its weight behind 3GIO, the Intel-backed third-generation I/O spec., in opposition to arch-rival Nvidia's support for HyperTransport, the AMD-backed third-generation I/O spec.

Cynics will argue that ATI's support was bought at the price of a Pentium 4 bus licence. The truth of the situation is probably more prosaic. ATI makes graphics cards that connect to the host PC though either its PCI or AGP bus. Since 3GIO is not only the successor to both of these technologies, but the one that will unite them, it makes a lot of sense for ATI to stick its oar in as soon as it's able.

Nvidia may have to support 3GIO at some future time for the same reason. Some unnamed members of the HyperTransport Consortium are working on an adaptor card connector schema, but it doesn't appear to be priority to Consortium members, at least as far as their documentation goes. And, indeed, AMD's support for 3GIO through its co-directorship of the PCI Special Interest Group, the PCI spec.'s steering committee.

HyperTransport development seems - for now at least - more focused on chip-to-chip communications. Hence Nvidia's interest - it's using the technology to connect the north- and south-bridge chips that comprise its nForce chipset. That chipset in turn connects to AGP and PCI buses.

ATI too is getting into the chipset business, with product expected by the end of the year. That's too early for 3GIO, which isn't likely to emerge in products before 2003. It is, of course, plausible that ATI may yet join the HyperTransport Consortium too, but since it's looking at connecting its own north-bridge part to other companies' south-bridges, we suspect not, at least not yet.

There's certainly no reason why HyperTransport and 3GIO can't co-exist. We can see a world of HyperTransport-connected chipsets connecting the CPU to the rest of the system across 3GIO direct graphics and, via the south-bridge, switched 3GIO add-in cards.

The HyperTransport Consortium's apparent disinterest in adapter card connector specs. and the 3GIO team's keenness on said, along with AMD's PCI-SIG vote of 3GIO suggests the HyperTransport camp has conceded that part of the system to its rival.

3GIO, on the other hand, is still being positioned as a chip-to-chip interconnect that can be used to link north- and south-bridge parts, so AMD is presumably hoping that, with its 12-month lead in the market, its technology will become a de facto standard or - ideally - the template for that aspect of 3GIO. HyperTransport as specialised sub-set of 3GIO, anyone? ®