I have found an easy method to patch Asus bios for speed stepping. You just need AMIAptioTool to identify the 2 CpuPei modules, extract them. Then do a search and replace on the two modules with a hex editor (all credits to DHP for this fix):800018EB050D0080to000018EB050D0000There should only be one instance of this string in each module.
Then use the tool to replace the existing modules with the patched ones. Voila! Now I found that the AptioTool will work on 4Mb EFI bioses (such as the P8P67M-Pro) but not the new 8Mb ones (such as the Gene-Z). So I use Phoenixtools to replace the patched modules (it has an option to pause the patching so you can replace original modules in the DUMP directory with patched ones. This has worked for me on all bios variants for the P8P67M-Pro and Maximus IV Gene-Z.
REMEMBER that patching a bios is a risky business, so do so at you own risk.
Do you think this can work on MSI mobos ? I'm trying to get Speedstep working for my P67A-GD65.
Speedsteper is not working for me.