Asus Crams Three GPUs onto a Single Graphics Card

Barence writes "PC Pro has up a look at Asus' concept triple-GPU graphics card. It's a tech demo, so it's not going to see release at any point in the future, but it's an interesting look at how far manufacturers can push technology, as well as just how inefficient multi-GPU graphics cards currently are. 'Asus has spaced [the GPUs] out, placing one on the top of the card and two on the underside. This creates its own problem, though: attaching heatsinks and fans to both sides of the card would prevent it from fitting into some case arrangements, and defeat access to neighbouring expansion slots. So instead, Asus has used a low-profile heat-pipe system that channels the heat to a heatsink at the back of the card, from where it's dissipated by externally-powered fluid cooling pipes.'"

Comments

2 GPUs is the limit, for now.

[default luser]

It's not necessairly a limit of the board design, but a limit to what game engines can be optimized for. Most game engines do not scale well beyond two cards, as can be seen here:

http://www.xbitlabs.com/articles/video/display/zotac-9800gx2.html

While there are a few key games that get no boost out of 2-way SLI, the vast majority of games do see improvement. 3-way, on the other hand, can actually cause WORSE performance.

It probably has to do with limitations on how the SLI/Crossfire drivers can fake-out the game engine. There are probably limits to how many frames the game engine allows to be in-flight at once, limiting how much performance boost you can get from AFR SLI. And although you can get around game engine limitations with split-screen rendering, this mode needs specific game support, and shows less potential performance increase. Plus, split-screen rendering and has to be selected explicitly in Crossfire (AFR is the default).