как правило, самый главный пожиратель ресурсов - процесс kernel_task
его можно приструнить, подредактировав ACPI_SMC_PlatformPlugin.kext
spoiler
1) Open System Information (under Apple icon in upper-left, click About This Mac, click More Info)
2) Click System Report button, under Hardware, find your "Model Identifier" -remember this for later use
3) Navigate to /System/Library/Extensions an right-click, Show Package Contents of IOPlatformPluginFamily.kext
4) Open Contents/PlugIns and Show Package Contents of ACPI_SMC_PlatformPlugin.kext
5) Open Contents/Resources
6) Find your MacBookAir?_?.plist (? = your model identifier from step 2) and delete the file
7) Reboot! Remember, anytime you do a System Update, you may need to repeat this process
