THE STRETCH FROM late 2005 into early '06 has been a remarkably busy time in the world of PC graphics hardware. Most of it has been ATI's doing. Their CrossFire dual GPU technology was tardy, but it showed up to class just before the end of September. Shortly thereafter, ATI finally delivered its much-delayed Radeon X1800 GPU as part of a top-to-bottom lineup of new graphics chips, all among the first GPUs to be built on a 90nm fab process. Among other things, the Radeon X1800 XT put the company back on top in the high-end performance sweeps, however briefly. The welts had barely faded from the whooping NVIDIA laid on the Radeon X1800 XT with its GeForce 7800 GTX 512 when ATI countered with its new high-end GPU (right on schedule this time), the Radeon X1900. Not only was the Radeon X1900 XT the new fastest card on the block, but it got some help on the multi-GPU last week in the form of a new dual sixteen-lane PCI Express chipset, the CrossFire Express 3200.

Phew.

Now it's time for another round of new stuff, and the competition is tighter than ever. Today, NVIDIA is unveiling two GPUs powering three different flavors of video cards. Say hello to the GeForce 7600 and 7900 series, new mid-range and high-end graphics cards ranging from $199 to, well, very expensive. These introductions mark NVIDIA's transition in earnest to 90nm fab process technology, a place where ATI has been for a number of months.

Speaking of ATI, the folks there couldn't stand by and watch new GeForces arrive without doing something, so they've decided to unveil a new $249 Radeon card and rework their product lineup to include a range of more affordable options. We've tested the Radeon X1800 GTO alongside the new NVIDIAs.

Oh, yes. And we have the juicy details on the King Kong of PC graphics, quad SLI, where not one, not two, but four GeForce 7900 GPUs can pull together to squash all competition and raid your Swiss bank account.