How to limit cpu frequency in OS X?
I found this for your reading pleasure:
Mavericks: Native CPU/IGPU Power Management
Native Mavericks power management delivers the best combination of processor and graphics performance and efficiency. The ingredients are an installed processor specific power management ssdt, a compatible system definition and the native power management kext. Native Mavericks power management does not require specific BIOS settings or anything more than one boot setting to load the power management ssdt. Credit for the technique described to PikeRAlpha.
What changed between Mountain Lion and Mavericks power management? The existing processor frequency/power state reporting tools (i.e., MSRDumper, HWMonitor) stopped reporting power states between idle and max non turbo. This led to an incorrect conclusion that native Mavericks power management was not working. A new tool, Intel Power Gadget, shows Mavericks power management is working as designed.
To be clear, native Mavericks power management is not mandatory. The consequences are not severe. Performance is similar, however, higher temps (~10 C), more power (5-10 W) and sleep problems are likely.
Change Log
v1.1 - 4/4/14 - CPU PM/Core i3/5/7 xxx (1st Generation)/Core 2 and earlier (below) v1.0 - 4/2/14: Initial Release
Requirements
OS X/10.9.2 or newer Desktop/Laptop only Server, see Guide: Asus X79 OS X Controlled SpeedStep Stock Clock Verify OC, use ./ssdtPRGen.sh -f freq flag
Supported CPU/IGPU
Haswell/HD4600+ (Core i3/5/7 4xxx, 4th Generation) Ivy Bridge/HD4000 (Core i3/5/7 3xxx, 3rd Generation) Sandy Bridge/HD3000 (Core i3/5/7 2xxx, 2nd Generation)
Native Mavericks Power Management Recipe
System Definition - match processor generation/desktop or laptop ssdt - custom to installed processor kext - native IOPlatformPlugin.kext
Not considered
NullCPUPowerManagement.kext Safe Mode boot (-x) Discrete graphics