Overclocking is an easy way for users to get the most out of their hardware. For the most part, general users can just tweak a few things, bump up the voltage a little bit and in this day and age can normally get a nice little overclock on their CPU to gain some additional performance.
My final overclock that I was happy with came in at 4757MHz with the voltage technically being set to 1.400 in BIOS. However, I was able to boot into windows at 5000MHz or 5.0GHz but it was not 100% stable and while I could use it fine, some of the benchmarks I ran just did not feel right, which is why I back it done to 4.7GHz where I was 100% happy with it. At 4.7GHz everything felt right, there were no lag or freaky one off mishaps going on and this is where I personally felt most comfortable.
4.7GHz is still a nice little bump in performance as you have seen just by the benchmarks that were rant on stock and a 4.5GHZ OC setting. 5.0GHz is obtainable and I have a feeling that with a little more time, or if this had been an APU I purchased I may have tried to push it a bit harder.