It’s too early yet to make a final judgment about the success of NVIDIA SLI technology, but it is not a failure, that’s certain. When there were no compatibility and stability problems the technology boasted a very high efficiency: adding a second graphics card and enabling the SLI mode we could lift the performance 1.5-2 times, while the analogous technology from Alienware could give you only 40-60 percent relative to the single card.
We guess it is the GeForce 6600 GT SLI configuration that’s not very appropriate. A platform with two GeForce 6800 Ultra may be demanded by wealthy PC enthusiasts, but the “inexpensive” realization of NVIDIA’s multi-GPU technology proved to be not so cheap in practice: its price is comparable to the price of single top-end cards, and the latter have almost the same performance, but better stability and compatibility with the existing gaming software.
You maybe know that NVIDIA is not alone in its interest in multi-GPU solutions – this company is just the first to implement the concept in silicon. ATI Technologies is also planning to unveil its multi-GPU technology soon. It is already given a name – ATI Multi Rendering or AMR. This technology is expected to be more flexible than NVIDIA SLI: it will allow using different graphics cards from ATI and will free the user from the additional adapter – the information necessary to synchronize the cards will be transferred through the PCI Express bus. S3 Graphics is also preparing an analogous solution, so there’s going to be a wider choice of multi-GPU platforms very soon.
The results of the poll we conducted on our site (see this page for more details) suggested that NVIDIA SLI was not going to become a sensation among PC gamers. Only 5 percent of the participants said they wished to buy a SLI kit of a mainboard and two graphics cards. 15 percent more voted in favor of purchasing one card and then, some time later, another one. On the other hand, 45 percent of users are considering the possibility of buying a system with some version of the multi-GPU concept. That’s why we don’t think the new incarnation of the idea of multi-GPU graphics hardware is going to be a complete failure.