updated 04:15 pm EDT, Mon April 28, 2008
iMac CPU Origins
The 3.06GHz processor and fellow chips in Apple's new iMacs are part of a special run of Intel's existing technology rather than an early introduction of Centrino 2 technology, Intel has confirmed with Electronista. Although the processors match the same core clock rates and 1,066MHz system bus speeds as those for the upcoming platform, the processors are now known to be unlisted speed grades that include special support for the faster bus speeds (up from 800MHz).
The top 3.06GHz chip, which boosts past the 2.8GHz official speed of current models, demands 55 watts of power at its thermal design limits and is designed for "mobile on desktop" systems, such as large gaming notebooks and crossover PCs. The energy draw and resulting heat rule the current processor out of more typical notebook designs. Current processors top out at 45 watts, with most consuming 35 watts or less. The upcoming Centrino 2-era processors will consume 25W and 35W in most models when they arrive in June, Intel adds.
The mainboard remains based on the same "Santa Rosa" chipset as for earlier iMacs and MacBooks.
Apple has a history of using off-specification processors for many of its computers based on Intel platforms. The company was the first to use a 3GHz Xeon 5300 in its Mac Pro workstation and also used a 2.8GHz Core 2 Extreme in the first aluminum iMac. Its highest-profile example is the use of a limited ultramobile CPU in the MacBook Air that uses packaging technology from Centrino 2 with a current-generation processor core, permitting it to use just 20W of energy while still running at 1.6GHz.