At last, AMD has officially launched its RV670, the RadeonHD 3000 series.The battle with Nvidia's new G92 is on.But the Radeon HD 3000 series could also mark the end of an era. It could beone of the last single-GPU graphics ranges we see.

Strength in numbers

Very few details have emerged about either ATI's or Nvidia'snext generations after the silicon just recently released. But, of the two, ATIhas been a little more candid.

The R600 was ATI's big new core technology, with itsintroduction of a unified shading architecture using stream processors insteadof the traditional divide between pixel and vertex shading units. The R670 isessentially a tweak and die shrink of R600, not a major technological leapforward.

So, instead of developing yet another radical new core,ATI's next step beyond R670 appears to be to take advantage ofever-miniaturising process tech, and fit more than one R600-based core on asingle card - something a few manufacturers such as GeCube are already doing.In fact, the forthcoming R700 will allegedly have up to eight cores on a singlecard, or maybe even a single chip.

As I've commented here before, ATI has had multi-GPU technologyfor many years, and CrossFire is clearly here to stay. Tacked at the end of theRadeon HD 3000 series announcement (and our news article about it) was theofficial launch of CrossFire X, supporting three or four cards instead of justthe original pair. Clearly, ATI is hoping that persistence will make thistechnology more widely accepted, before it becomes the norm in the R700.

Nvidia hasn't released any details at all about its nextgeneration, and there aren't even vague rumours circulating. But considering that SLI has now officially moved up to threecards, and the GeForce 7950 GX2 sported twin GPUs back in 2006, it's not hardto imagine that Nvidia will be considering a multi-core future as well.

Go forth and multiply

In the past, I've been somewhat critical of multi-graphicscard configurations, because so few people actually run them.And I remain sceptical, for a number of reasons.

For a start, it has taken ages for multi-core CPUs to beproperly supported by software. Dual-core is now almost universal, quad-corehas become affordable, and eight-core CPUs could be arriving at the end of2008. Yet there are still plenty of new applications which get little or nobenefit from more than one core.

Multi-graphics has actually proven itself a bit morebeneficial, as games don't necessarily have to be coded specifically to supportit. However, not every title gets a boost - particularly the real-time strategygenre, as it's so CPU intensive. And there are still plenty of games whichsimply don't work properly with CrossFire or SLI enabled.

So a multi-core strategy in graphics might not provide thehuge leaps forward in performance with older games we saw, for example, betweenthe GeForce 8000 series and previous 7000 series.

Coming, ready or not

However, I've also recently been playing with Dell's latestInspiron XPS notebook, the M1730. Aside from being the first portable to boaston-board AGEIA PhysX hardware acceleration for game physics, it also sports notone but two Nvidia GeForce 8700M GT mobile GPUs as standard, with no othergraphics options.

On its own, a single GeForce 8700M GT can't match Nvidia'stop 7000-series mobile GPU, the Go 7950GTX, but two together in SLI can beat it- and offer DirectX 10 support as well. If you don't run SLI mode, one GPU canenter a low power mode after a reboot. Since the 8700M GT consumes just 30Watts, compared to the 7950 GTX's 45W, that's a significant power saving.

So SLI seems to make some sense for enthusiast notebooks,giving them 3D grunt when enabled, and lower power consumption when not.Nvidia's Hybrid SLItakes a similar strategy, but using integrated graphics alongside discrete. Inother words, multi-GPU is starting to show some potential benefits beyond thefew per cent of extreme gaming enthusiasts who currently use SLI or CrossFire.

I still can't see mainstream users rushing out to get CrossFireX or Triple-SLI. Nevertheless, with GPU architectures like ATI's R700 on thenear horizon, it looks like the technology will be coming to a desktop near youanyway in the very near future - as a standard feature of the next generationof graphics chips.