AMD : RS600 / Crossfire

Following on the heels of yesterday's post about textured video support, somebody popped in with a question about support for the RS600. The RS690 chipset is the better known support chip for the AMD processor platform, and the one named explicitly on AMD's own development page : http://ati.amd.com/developer/open_gpu_documentation.html The RS600 is the lesser known, and lesser sold, Intel processor compatible chipset, and a sore point with Novell devs. It seems that ATi marketing didn't remember selling the RS600 chipset... and who could blame them... and were a bit confused when the first tests of the RadeonHD driver weren't working on a supported platform.

So, that brought up a question of my own. At one point Intel produced chipsets and motherboards that carried official support for ATi crossfire. I know this because I actually have one of those boards thanks to a generous donation. Ergo, I posed this question:

Saist: drat... Bridgman left... oh well : since he'll probably get it anyways : question about Multi-GPU support, e.g. : Crossfire : Some of the official Intel chips and motherboards support Crossfire rendering, e.g. the D975Xbx :: http://www.intel.com/products/motherboard/D975XBX/index.htm :: although multi-gpu support is probably far off down the RadeonHD roadmap, will those who have the intel chipsets be able to use multi-gpu support? Or "not enough information at this time" ?

The answer... was a bit surprising:

bridgman: Saist: too soon to tell. If we need to use information obtained from Intel under NDA in order to make Crossfire work on an Intel chipset then we would need Intel's permission to release the info in open source form. That said, if we can make a single card work on the chipset then there's a decent chance we can make two cards work

Next question though... why is this important? Well, one of the questions that has been posed before is why do Open-Source drivers matter? If a particular vendor such as Creative, ATi, and Nvidia release quality proprietary drivers on a regular basis... why should users care if the driver is opened up?

I might be reading between the lines here, but from the way Mr. Bridgman phrased his eventual response, it would seem that CrossFire support under RadeonHD would work on any platform that could recognize two GPU's. Taken out of context, it might be possible that the Open-Source driver could deliver CrossFire support where AMD legally cannot... on chipsets like the Nforce SLI series.

That is one of the direct benefits of an Open-Licensed driver... you can support platforms that the original vendor may not be able to support.