X-bit labs

S3 Graphics Enables Multi-GPU

by Anton Shilov

[ 05/05/2006 | 12:48 AM ]

Virtually all desktop graphics companies that are on the market today have tried to play with multi-processor technologies in one form or another and both ATI and Nvidia have been successfully promoting their CrossFire and SLI among consumers. But for S3 Graphics, who has about 1% market share, enabling a multi-graphics processing unit (multi-GPU) technology is something new, as this is the first time in life for the company.

S3’s latest Chrome S27 top-of-the-range model features the company’s revamped fourth generation DirectX 9.0-supporting micro-architecture, a bit evolved from the GammaChrome introduced in 2005. The S27 features 8 pixel processors and 4 vertex processors as well as flexible PCI Express support, which means that the chips can function in any type of electrical PCI Express slots – x1, x4, x8 and x16. The model S27 graphics card sports graphics chip clocked at 700MHz with up to 1400MHz GDDR3 memory (128-bit bus).

While S3 positions its Chrome S27 at sub-$100 market and below, where price matter much more than some other characteristics, the company has decided to spend time and resources to enable ability of two Chrome S27 boards in tandem, thus, providing higher performance. While the technology was announced formally quite a while ago, The Tech Report web-site was the first media to check it out very recently.

The web-site revealed that just like other multi-GPU solutions, MultiChrome relies on a database of game profiles in order to determine when to do its thing and which load-balancing method to employ, if the game does not have a profile, it will simply run on one card, without the performance benefits of dual GPUs. S3 currently has profiles for about 50 games, including many of the more popular titles of the past few years, but does not allow users to tweak or create game profiles themselves.

Right now, S3 has only implemented one of the two most common load-balancing techniques used in dual-graphics solutions: alternate frame rendering (AFR). AFR is used widely because it offers the best performance scaling by boosting both vertex and pixel throughput. S3 says the other technique, split-frame rendering (SFR), is coming soon but is not yet enabled in its current drivers.

The author says that the MultiChrome technology is relatively mature, he did not experience a significant amount of crashes, or something like that. However, performance-wise, the MultiChrome is not that good.

“I’m somewhat disappointed that the total peak performance S3 can offer when it combines two of its best GPUs isn't terribly compelling. I had really hoped going to dual GPUs would allow S3 to offer some form of solution that might appeal to PC gamers and enthusiasts. Too much has happened since MultiChrome was first announced, and that’s simply not the case. There’s just no way this is a $200 graphics solution on the order of the GeForce 7600 GT,” the report concludes.

• The Tech Report: S3’s MultiChrome Dual-GPU Technology.