44. Is Notebook SLI The Future?

Even though we couldn't land any SLI-equipped notebooks for testing in our labs in time for this review (we'll explore some reasons why in our conclusion to this story), this won't stop us from making some statements about notebooks and SLI. As the recent past and our tests have already shown, a doubled up system with SLI can lose its value very quickly. One GeForce 7800 GT is faster than two GeForce 6800 GTs, and one GeForce 7900 GTX is faster than two GeForce 7800 GTs. Doubling up on graphics cards always means spending more than on a single card of the next graphics processor generation.

Even more importantly, consider that only 30 percent of current games support SLI operation, by our best guesstimate. If SLI is supported, frame rates climb by up to 80 percent, depending on the resolution and graphics quality settings chosen. A good example is the game Call of Duty, which even offers a special performance boosting SLI switch in its graphical menu.

Disadvantages of SLI include: higher power consumption, more noise output from a second fan, and higher heat output. And for games where SLI isn't supported, SLI configurations actually run slower than single-card configurations. That's when it's smart to set rendering in the graphics driver to single card mode, to keep performance losses to a minimum.

Owing to the aforementioned issues, you must consider carefully whether or not it makes sense to spend big bucks on an SLI notebook. It may make more sense to turn over your new notebook purchases more frequently instead. The "old" notebook can always help to partially fund the new one, thanks to online auction houses and quick hardware turnover through such outlets.

In this connection, it's also interesting to consider the following announcement: As of July, Nvidia plans to release a driver that will support physics effects in 3D games using the second SLI graphics card. This could motivate even conservative vendors to develop notebooks with doubled-up graphics cards. In any case, this would let users decide if the second graphics chip is better suited for physics effects or increasing frame rates.