MacWorld has taken a look at the 2011 Build-to-Order MacBook Airs that Apple released earlier this month.
The reason being, the BTO models have the option of an Intel Core i7 for both the 11-inch and 13-inch MBAs. Normally they come with ultra-low-voltage (ULV) Intel Core i5 CPUs
11-inch Standard: 1.6Ghz Intel Core i5
11-inch BTO: 1.8GHz Intel Core i7
13-inch Standard: 1.7GHz Intel Core i5
13-inch BTO: 1.8GHz Intel Core i7
As the review points out, the Core i5s that ship with both MacBook Airs already have Hyperthreading and Turbo Boost, so the main difference is clock speed and a larger L3 cache.
To upgrade the 11-inch, it costs $150 USD. 13-inch? $100.
The big differences on the 11-inch MBA: Parallels WorldBench (for Parallels Desktop VM software) saw a 25% increase, and Cinebench, iTunes encoding, Pages ’09 importing, and zipping a 4GB file saw right around a 20% increase. Keep in mind that both models use flash memory for their hard drives – the same as what you see Solid State Drives (SSD).
With the 13-inch MacBook Air, the differences are not nearly as much – Parallels WorldBench saw a 10% increase, and unzipping a 4GB file saw a 21% increase in performance. Otherwise everything else was very low.
Graphics wise, there isn’t much difference – the mid 2010 MacBook Airs had dedicated NVIDIA graphics chipsets and the new Intel HD Graphics 3000 didn’t perform much better. The CPU upgrades in the mid 2011 models were clearly the main difference.
Full Article: MacWorld