It's no secret that Intel has soared while AMD has stumbled through the past year. In fact, as of press time AMD's worldwide share of the notebook microprocessor market had sunk to a paltry 12.6 percent compared to Intel's 86.5 percent. That's a dramatic fall-off from a high of 18.9 percent in the third quarter of 2007. Part of the problem is that AMD is still working to integrate the recently acquired ATI, but whatever the reasons, Intel has forged ahead with smaller and more power-efficient 45-nanometer processors while AMD has been stuck churning out 65nm chips for what now seems like eons.

On the other hand, in many cases, systems with AMD inside are considerably cheaper than their Intel Centrino–powered counterparts. For instance, we surveyed the price difference between three notebooks available with both Puma and Centrino 2 and found, on average, that Centrino 2 notebooks cost $217 more than Puma ones with all other components being equal. Each company claims to offer superior integrated graphics, battery life, 802.11n wireless strength, and improved overall performance. That's nice, you say, but which is better?

To find out, we decided to put the two platforms to the test. To do this, we used two notebooks, identically configured with the exception of their CPU, graphics card, and wireless radio. These 15.4-inch systems had 2GB of RAM, 160GB hard drives, integrated graphics, and DVD burners with Blu-ray. Our Centrino 2 system was powered by 2.26-GHz Intel Core 2 Duo P8400 CPU and Intel's Graphics Media Accelerator 4500, while the Puma machine had a 2.2-GHz AMD Turion X2 Ultra Dual-Core Mobile ZM-82 CPU and ATI Radeon HD 3200 graphics card.

So, what's the difference? We put these near-twin notebooks through nine grueling tests, not just to see if Intel's Centrino 2 is worth the premium, but to nail down which platform is best for which type of user.