Apple's not only pushed the envelope with the industrial design of the MacBook Air, but also pushed Intel to deliver some advanced CPU technology, according to a new report. Rather than use Intel's newly introduced 45-nm Penryn mobile chips, the company used a modified version of current 65nm mobile chips with smaller packaging. According to Anandtech, the new MacBook Air uses a specialized version of Intel's Merom-based Core 2 Duo chip, the same chip used in Apple's other laptops (and from other PC vendors); however, it appears that the chip is actually uses technology originally slated to ship with its next-generation Montevina platform later this year.

According to the report, the CPU comes in a package that was originally reserved for mobile Penryn due out in the second half of 2008 -- using the Montevina SFF Centrino platform. Intel apparently accelerated the introduction of the packaging technology specifically for Apple, the report says.

While Intel was initially coy about the technology, a follow-up email from the company notes that the MacBook Air chip is not a low-voltage chip, but a specially made version of its standard Core 2 Duo.

"The MacBook Air uses the Intel Core 2 Duo Processor and Intel 965GMS chipset with integrated Gfx using a new miniaturized package technology," Intel explained. "This new CPU and chipset allows for approximately 60 percent reduction in total footprint. The Core 2 Duo Processor TDP is 20 watts. The Macbook Air is using existing Core 2 Duo technology with a lower voltage spec in a new miniaturized packaging design. It is not a ULV processor."

Thus the CPU and chipset are both using advanced packaging technology for a smaller footprint, while still using the current generation mobile Core 2 Duo chips (perhaps to save costs associated with the newer Penryn chips). Anandtech notes that the 1.6GHz chip in the MacBook Air runs at 1.0V - 1.25V, while the 1.8GHz version runs at 1.1125V - 1.25V -- both less than the standard mobile Core 2 Duo, but more voltage than the Low Voltage chips.

"The TDP of these not-quite-low-voltage Core 2s reflects the increased voltage," Anandtech writes. "While the L7700 and L7500 have a 17W TDP, the chips used in the MacBook Air are rated at 20W." Standard mobile Core 2 Duo chips are 35W parts.

While it's unclear why Apple's chose a modified version of the Merom Core 2 Duo chip rather than standard low-voltage parts, the report says the that an avoidable side-effect may be a hotter notebook.