First of all looking at the

Mac Book Air from the Apple website there are 2 versions of the 15" Air and they have the 2.3 and 2.6 i7. The turbo boost which is overclocking power built into the processor is 3.3 and 3.6. The 2.6 ghz processor is the I7-3720QM. The 2.9 ghz processor is the i7-3920XM and is classified in the Extreme category.

http://www.intel.com/content/www/us/en/processor-comparison/compare-intel-processors.html?select=laptop

The processors are made by Apple or Dell they are made by Intel and placed in both machines. AMD is an aternative company to Intel and many say their high end processors don't match the Intel high ends.

here is a search at Newegg.com with laptops at 2.6 ghz processor speeds and above. It includes 2nd and 3rd generation i7 processors.