Why are some of my games freezing after cpu and gpu overclock

[CommunistSquared]

After recently buying the z87x-ud4h along with a i7 4770k, I decided to overclock. I overclocked my cpu from 3.5 to 4.2 ghz. As I didnt scrape up enough for a video card I also overclocked the onboard intel 4600 hd gpu from 1200 to 1600 mhz. All of this is cooled by a cooler master hyper 212 evo, temps are good in the higher 30's. After some tweaking the system seems to run somewhat fine until I decided to start up farcry 3. I was able to play it fine on minimal settings before the overclock, but after my computer just completely froze up at the loading screen. It didnt respond to alt f4, ctrl alt delete, just nothing, forcing it to power off. This happens every time. What is the reason to this? Im pretty sure all my drivers are up-to-date.

 

[Tradesman1]

May need more vCore (CPU voltage) to support the OC

 

[CommunistSquared]

Tried raising cpu voltage, seems like thats not the problem