This may be repetitive and I apologize, but I have been trying for over a week now and can't seem to figure out what the problem is. Even if it can't be solved (without purchasing new components) I'd like to know.

Motherboard: Biostar A88MQ GPU: Radeon R7 360 PSU: EVGA SuperNOVA 650 RAM: 8GB 1600MHz Ballistix CPU: A8 6600K (3.9GHz)

I purchased the scythe fuma to ensure I'd run into no cooling problems, and I haven't.

I have my CPU stable at 4.5GHz @ 1.381V.

When I move up to 4.6GHz, I can boot at 1.4V, but crashes 5 minutes into a stress test.

Raising the voltage 0.0062V makes my CPU drop to 3.6GHz. http://imgur.com/a/QZNoT Any more voltage makes it throttle more.

I purchased little copper heatsinks for my VRM's and installed them. http://imgur.com/U2qR9tP

What could be the problem here? The only BIOS setting I have is C6 and it's disabled, like it should be.