Hannover (Germany) - While the week began with ATI's announcement of a new high-performance mobile GPU, Nvidia waited for the opening day of the huge CeBIT conference to announce no fewer than four new product entries that almost completely redefine Nvidia's product spectrum. Included in the mix is its own high-end notebook GPU, the extension of SLI to the notebook platform, and the expansion of SLI on desktops.

Nvidia's development strategy is to offer new products for the three basic market tiers - performance, mainstream, and value - separately, rather than apply the old "trickle down" theory, where performance-class cards become next year's mainstream fare. So bringing up the middle today, Nvidia announced the G73 chip, which premieres today in the GeForce 7600 GT, which replaces the 6600 GT as the company's price/performance leader.

Underscoring the importance of the hundreds place in today's graphics card nomenclature, Nvidia included among its talking points this week that the 7600 GT outperforms ATI's X1600XT, while the 7900 GT outperforms the X1800XL. The game is changing; its premise is no longer about overall capabilities, but relative performance within each card's designated class.

All three GeForce cards announced today, says Nvidia, supports Microsoft's DirectX 9.0 Shader Model 3.0, which represents perhaps the highest level of graphics technology made possible today by a standard feature of Windows. But "today" never lasts very long; and as we've covered here, Microsoft's plans for Windows Vista include exclusive support for a premium performance tier, for graphics hardware designed to support DirectX 10. Up to this point, both Nvidia and ATI have been reluctant to state whether even their current top-of-the-line graphics cards will support DirectX 10, even though developers' versions have already been made available for laboratory testing.