June 30, 2012, 7:47 AM — We’ve posted benchmark results and a full review of the 2012 MacBook Airs, but the work in the lab has not stopped. Apple usually offers optional upgrades that allow you to tailor a standard-configuration system to best suit your individual needs. Macworld Lab ran performance benchmarks on two MacBook Air build-to-order (BTO) models, and the results show that while both custom systems were faster than the high-end stock MacBook Airs, the upgrades to the 11-inch gives a bigger performance bang for the buck.
11-inch BTO MacBook Air ($1649)
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Our custom 11-inch MacBook Air takes the stock high-end $1099 model and upgrades the processor from the standard dual-core 1.7GHz Core i5 to a dual-core 2.0GHz Core i7, a $150 option. Our custom system also has 8GB of RAM rather than the stock 4GB, an extra $100. Finally, we upgraded to 256GB of flash storage from the standard 128GB for an additional $300 for a grand total of $1649 for this BTO MacBook Air.
While the BTO system ended up costing us 50 percent more than the stock high-end model, it boosted overall performance by 21 percent. Every single test we ran benefitted from the extra RAM, extra storage, extra processing power, or a combination of the upgrades.
Aside from the faster clock speed, the dual-core 2.0GHz Core i7 upgrade offers 4MB of shared L2 cache as opposed to 3MB on the Core i5. Both the Core i5 and Core i7 processors offer Hyper Threading which allows the processor to offer four virtual cores, and Turbo Boost which lets the processor crank itself up to faster clock speeds when necessary (up to 2.6GHz on the 1.7GHz i5 and up to 3.2GHz on the 2.0GHz Core i7). The dual-core 1.8GHz Core i5 in the stock 13-inch MacBook Air can reach speeds of 2.8GHz using Turbo Boost.
In processor-intensive tasks, the BTO 11-inch MacBook Air’s results are between 12 and 18 percent higher than on the stock 11-inch model. Our file duplication tests are 18 percent faster on the BTO 11-inch model, and Aperture import and process test is 22 percent faster.
13-inch BTO MacBook Air ($2199)