To get back to the ''how do you OC?'' question..
I use a method hardly anyone uses nor recognizes.
When I buy a piece of hardware I have certain expectations of it in terms of overclocks so I just test whether it meets that expectation. If it doesn't i'll sell it 90% of the time again.
Like my GTX770 Lightning. I expected / wanted it to do 1400Mhz+ on max volts and RAM to do 1800Mhz.
So, I set max volts and tested a +200 offset (1424Mhz) clock. Instant crashes all round. Kept backing down 10Mhz till it was stable at 1385Mhz on 320.49 but the new 326.41 cut that down to 1355Mhz.
Now as you see, it won't even get close to the 1400Mhz, more like 1360Mhz max. But the VRAM does 2000Mhz easily and maybe even more then that so it can stay for now. 7970 Lightning is underway just for testing. Might keep it if it does my expected 1300Mhz+ core. (bought it for €200 from a guy who thinks it's broken but it's his €20 920w PSU crapping out).
2500K same story. I wanted a 5Ghz+ CPU. Bought 5 of em, all maxed at aprox. 4.8Ghz.
Sold them all, bought another 3, one broke due to crap board so got a new one from Intel.
One of those 3 did 5.1 @ 1.448v and had the coveted 59 multi so I sold it for a lot. The Intel RMA did 5.1 @ 1.392 and 5.3 @ 1.472v. Now THAT meets my expectations so can stay
(unless I come across a 5Ghz+ 3770K delidded or not yet so I can do it)