Microsoft is keeping many (most?) details about its next-generation Xbox console under wraps, but at least one of the choices that Redmond has made public is stirring a spirited debate. Will Xbox Next, as it's now being called, play games designed for the original Xbox? Your answer depends on who you ask.

Jen-Hsun Huang, CEO of Nvidia, says his guess is that the next Xbox won't be compatible with the old one. "It's virtually impossible on many levels," he adds. "On an intellectual-property level. On practical levels, too." When asked to explain (might this be sour grapes talking?), Huang says for cost reasons, Microsoft isn't likely to be willing to put additional chips in the box to ensure hardware compatibility. Moreover, he suggests that current Xbox games make use of Nvidia's proprietary graphics shaders and that Microsoft might have to license them to use them again.

By contrast, Dave Orton, president of ATI, says, "It's not outside the realm of possibility to make a compatible Xbox." He didn't discuss specific products his company is making for Microsoft, but he says that if you just consider the timing (about five years) between the consoles, then Moore's Law dictates that the new machine will be eight times as fast as the old one. With such an increase in raw processing speed, Xbox Next should have plenty of horsepower to emulate the old games via software. That is, the new hardware will be fast enough to execute the old games even if they have to run through software translation. On the processor side, Microsoft might have to employ its Connectix software to get the Intel code to run on the IBM PowerPC. That problem raises the prospect of additional costs and engineering efforts. "It's not a trivial amount of work," says Dean McCarron, an analyst at PC chip market researcher Mercury Research in Scottsdale, AZ. "It will be a massive task of integrating different technologies."