you will most likely need to patch your current AICPUPM kext once you have a working system. then remove null cpu. you will also need to find an smbios that works well for PM for your core. and an ssdt.aml there is a nice guide here http://www.insanelymac.com/forum/topic/295587-power-management-for-sandyivy-bridgehaswell-cpus/