Overclocking G3258 on MB MSI H81M-P33v2

[Guest]

I'll be brief. I need help about overclocking on my rig:
MB: MSI H81M-P33v2 (BIOS 10.5)
CPU: Intel G258 (OC'ed to 4.2GHz)
OS: WIndows 8.1 x64
RAM: DDR3 2x4GB.
Everytime i reboot my PC, the CPU clock speed always return to it's stock speed 3.2GHz. What should i do to keep my OC setting even after rebooting.

This might be simple question, but i'll appreciate it if you help me.
Thank you.

 

[truegenius]

do you use some software to overclock or do it in bios ?
and which heatsink you have ?
if you you bios to overclock then does it reflect overclocked speed in cpuz ? and have you tested for stability and maximum temperature ( keep it below 70'C )

 

[Guest]

do you use some software to overclock or do it in bios ?
and which heatsink you have ?
if you you bios to overclock then does it reflect overclocked speed in cpuz ? and have you tested for stability and maximum temperature ( keep it below 70'C )

I did it via BIOS.
Here's my configuration:
Image 1
Image 2
Heatsink: CM 212X

Before the reset, it shows 4200 MHz.
After reset, it return to stock speed 3200 MHz, but the voltage configuration still the same one from when OC.
Yes, i already test stability and temp, no problem.
Is it possible that CMOS battery causing this?