Today's question comes from Izzy via our reader feedback page. Don't forget to visit our friendly forums too if you have something that needs answering.

Q: I'm interested In nVidia's new SLI technology, but I'm confused about a few points... First of all, can you use any matched pair of nVidia videocard with one of the SLI-capable motherboards? Do they even need to be matched? Is it going to be compatible with all games? Is buying two videocards going to be worth it versus one good one? and most of all, is this going to be an nVidia-exclusive thing? Sorry about all the questions. Any input would be great.

A: There's a lot to cover with SLI, so a little confusion is understandable. Here's the facts as they currently stand. Currently, the only SLI compatible GPUs are the GeForce 6600GT, and the various 6800-based chips. The cards do need to be matched, apparently because the video BIOS of both needs to be the same version.

An SLI 'profile' needs to exist in order for a specific game to support the technology. Without this profile, SLI will not function and your system will default to using only one of the videocards to render the game. On the bright side, nVidia's drivers already include profiles for all of today's most popular games, and they will be adding more with each update. Also, future driver revisions will allow users to create their own SLI profiles apparently.

From what we've seen so far, two 6600GT cards running in SLI-mode are about equal to a single Radeon X800XT card, so given the relative prices of the two, it looks like SLI is going to be a cheaper way to go. Of course, you will need an SLI-compatible board, and these are currently not cheap at all. As for exclusivity, VIA has already announced a twin 16x/4x PCI Express slot chipset which they say will work with two PCIe cards, but this will apparently not be SLI compatible (though it will support 4 monitors). ATi no doubt has some future plans in the same direction too, but nothing concrete yet.

We've been reviewing a lot of SLI hardware in the test lab over the past couple of weeks, so watch for some new reviews soon, along with some juicy benchmarks.