I was overclocking for about 2 or 3 months before this started happening. But ever since I started playing more intense games like FarCry3 or Metro on max my mother board started making this beeping noise. At first I thought something was failing and did the whole running around the whole system checking for every little thing. Then I read somewhere check the PSU and check going straight to wall outlet. The crazy thing was it worked my PSU was fine but if I plug my system directly into the wall there's no beeping. Now the problem that scares me is I had my system on a 750W battery backup serge protector. So do I risk running i5 2500k at 4.2Mhz and GTX560ti on 925 Mhz core clock on straight outlet or just say screw the overclock and play it safe with stock everything? The other thing that was confusing when testing to see what the problem was is I did prime95 for over an hour and it didn't beep. Then I did the heaven benchmark and no beeps so must be when everything is working together the extra power is needed.
Graphic Cards: 2 GTX 560 Ti 2GB in sli
Case: Antec Three Hundred Two
SSD: Crucial M4 128GB SATA III
SSD: Munchkin Enhanced Delux 120GB
Hard Drive: HITACHI 500GB
Processor: Intel Core i5-2500K
RAM: CORSAIR Vengeance 8GB
SAMSUNG CD/DVD Burner
Operator: Microsoft Windows 7 Home Premium 64-bit
COOLER MASTER Hyper 212 Plus
PSU: XFX PRO750W XXX Edition Semi-Modular
Graphic Cards: 2 GTX 560 Ti 2GB in sli
Case: Antec Three Hundred Two
SSD: Crucial M4 128GB SATA III
SSD: Munchkin Enhanced Delux 120GB
Hard Drive: HITACHI 500GB
Processor: Intel Core i5-2500K
RAM: CORSAIR Vengeance 8GB
SAMSUNG CD/DVD Burner
Operator: Microsoft Windows 7 Home Premium 64-bit
COOLER MASTER Hyper 212 Plus
PSU: XFX PRO750W XXX Edition Semi-Modular