So apparently you can't overclock the g3258 on an Asus H81M-K
. Even tried bios modding it, managed to unlock the ratio multiplier, but the cpu speed was still stuck on 3200mhz.
With nothing to lose, I crossflashed the H81M-C
bios on it. I was fairly sure it would brick, but everything seems to be working so far.
Time to fine tune it then I guess.
EDIT: In case new users stumble upon this. I used UEFITool to unpack the C bios (3501) and force flashed the rom using a special version of AfuWin64 and the following command in cmd.(yes I flashed it while running windows)
afu64.exe H81M-C-3501-unpacked.rom /GAN
Restart your PC now and go into your bios, it should now say H81M-C at the top and you should be able to go past the 32 multiplier and change all kinds of voltages.
Made a small package containing the afuwin version and an unpacked C model bios (3501):