Can't Overclock past 1.6 or 4.2 Ghz - HELP!

[speedyrazor]

Hi, I am having issues overclocking my Asus Z77 Sandy Bridge system.
I have followed many Asus overclocking guides, I am aiming for a 4.5 Ghz overclock, so I adjust the CPU ratio to 45 and up the CPU voltage, and a couple of other bits and bobs, but thats the essential.
If I use the iMac 13,2 system profile I can get up to a maximum of 4.2 Ghz, using HWMonitor and GeekBench to test speed.
If I use anything else, Macpro 3,1, iMac 12,1, etc system profile I can only get up to a maximum of 1.6 Ghz.
I have tried lots of SSDT.aml files, downloaded some overclocked ones, used the multibeat overclocked one, created my own overclocked one, but no matter what I try I just can't get above 4.2 Ghz, either getting stuck at 1.6 or 4.2. Bios says turbo mode is happy at 4.5 Ghz.
I already have a pretty decent GB score of 14848 at 4.2 Ghz, but this limit thing is driving me crazy.
I have read many, many threads about this issue, and a few have resolved it, mainly either using Ivy Bridge CPU's or older OSX versions.

I am not using any of the MultiBeast NullCPUPowerManagement, or patched AppleIntelCPUPowerManagement as I have a patched Asus BIOS. But should I be?

Please could someone shed some light onto why this issue exists.
Here is my system:

Asus P8Z77-V LX (Latest Patched BIOS)
i7 2600K (Sandy Bridge)
8GB DDR3 Ram
AMD Radeon 6870 1GB


Cheers.

 

[Extra]

I'm going to bump this for a mutually strong desire to find a reasonable overlocking solution to the asus z77 tonymac install method. Those that I have tried (patch bios) have lead to inconsistent clock speeds or tubo ratios.

Every post I look into seems to have a dead end or incomplete?

There must be a solution out there somewhere because other methods of osx86 on these boards don't seem to have these issues.


Any success stories care to chime in?

 

[lordboogie]

I too am using a 2600k @ 4.5ghz Disable P-states and C-states in org.chameleon.Boot.plist, and enable Drop SSDT. This keeps my clock strictly between 1.6 GHz/4.5 GHz (no speedstep) depending on the task. My Geekbench scores reflects the change vs. no-changes, also it reports my CPU on 1.6/4.5 GHz in both istatsmenu and the Hardware monitor included with Multibeast.

 

[cluthz]

I used this trick on a Sandy +gigabyte z77:
http://www.tonymacx86.com/ssdt/60390-gigabyte-uefi-ssdt-dsdt-overclocking.html
THe turbo settings might apply to all z77, but I don't know.