i purchased MBA2012 CTO Corei 7 2.0GHz/ MEM 8GB / SSD 128GB. core i7 3667U, it support turbo boost, max multiplier 3.2GHz (x32, 1core), or 3.0GHz(x30, 2core). but check cpu-z 1.60.1.x64, it reports cpu multiplier x8 or x19. core speed does not reach 2.0GHz(x20). proccesor score of windows 7 experience index. MBA2012 CTO model's score is very low. MBA2011 CTO Core i7-2677M 1.8GHz(TB 2.9GHz) 6.9 MBA2012 Core i5-3317U 1.7GHz(TB 2.6GHz) 6.9 MBA2012 CTO Core i7-3667U 2.0GHz(TB 3.2GHz) 6.3 i think MBA2012 Core i5 is enabled turbo boost, but MBA2012 CTO Core i7 is disabled trubo boost, guess cpu max multiplier setting is wrong, and turbo boost is disabled in EFI to change boot windows. -- workaround(method): use ThrottleStop 4.0 later http://www.techpowerup.com/158795/TechPowerUp-Announces-ThrottleStop-4.0.html TRL(Turbo Ratio Limits) set to Maximun Turbo Ratio Limits. 1 core active 32/ 2core active 30. i have confirmed improvement that proccesor sore on windows7 experience index is up to 7.1. --- i guess this bug is a problem of setting the MSR (IA32_PERF_CTL:Target performance State Value) in EFI. it is assumed in the model CTO in the initialisation of the MSR in EFI, is to set the Target P-State and 19 at the time of turbo boost, and the root cause of the bug (I originally set 32 is correct). MSR 0x00000199 0x00000000 0x00001300 (bad) MSR 0x00000199 0x00000000 0x00002000 --- workaround(another method): use MSR Editor (CrystalCPUID) http://crystalmark.info/software/CrystalCPUID/index-e.html run CrystalCPUID.exe, Function->MSR Editor, set values and press WRMSR. repeat CPU1-CPU4. MSR Number 0x00000199 WRMSR EDX-> 0x00000000 EAX-> 0x00002000 --- fixed!! MacBook Air EFI Firmware Update 2.5 http://support.apple.com/kb/DL1592 This update is recommended for MacBook Air (mid 2012) models. This update fixes an issue where Turbo Boost does not activate when using Boot Camp, and resolves an issue where NetBoot does not function properly when using an Ethernet adapter.