e6750 default bclk is 333, if you want overclock much have to increase pci freq. but it have a benefit is your ram multiplier is low and oc e6750 don't affect ram too much. there are lot of thing to manage, try 105, 110, 120, 150... pci freq and which your gpu can't operate normal. then overclock bclk because you can stuck at 343mhz bclk if your pci e freq is 100mhz. I'm sure it don't damage any ssd hdd when oc pci e freq but it affect gpu, usb device. if you need you can take a photo of voltage in bios setting mb intelligent tweaker then I'll say more. these guide is enough for you to do a little overclock. If want overclock cpu as much as possible never use 2gb ram stick. It usually can't pass 1000mhz and will corrupt data, only use 1gb stick. I recommend use kingston or kingmax, I can normal overclock it more than 1400+mhz without any problem so I have free 1400mhz ram. This is for expert ocer