Except for the Intel i7-980x one of the better CPUs to overclock is the i7-3930k and since I have had both I can safely say that both were extremely easy to overclock. The i7-3930k is now my favorite CPU and I did at one time thought that nothing would replace the 980x.
I also think that the Asus Rampage IV board is a great match for this processor and while not being a great over clocker I was able to take it to 4.8ghz without much trouble. I don't believe in bleeding the last bit of over clock speed out of a CPU as I want stable clock speeds with reasonable temps and be able to maintain those under any conditions.
Normal stock speeds in the bios.
You will notice that the stock CPU clock speed is 3800mhz and that's the rated boost speed, also the memory clock is 1333mhz which is the default for this motherboard.
First type of over clock.
In the picture above you will notice that there are four preset overclocks that you can choose from.
a. Load normal overclock profile.
b. Load Gamers overclock profile
c. Load Extreme overclock profile (low current)
d. Load Extreme overclock profile (high current)
You also have a set of three preset overclocks in the CPU level Up option.
The thing about these presets is that they are set and tested at the factory by the Asus Engineers and are know working safe settings that you can use if you chose to do so. I like to try the different presets to see what the settings are that they used.
This is kind of a learning experience since these presets are already tested and it actually saves you a lot of time. Because you can take one of the better presets like say the Gamers one and set it in your bios and see what the settings are. Write them down and see what settings they changed and then you can unselect that preset and make your own starting with the safe settings from Asus.
The Gamers preset will take you to 4.7ghz but not on all six cores.
You will see that the first two cores are at a clock multiplier of 47 , the next at 46, the next at 45 and the last two at 44. However when gaming the first two or three cores will be giving you that high clock of 4.7ghz, 4.6ghz. You will also notice a setting above the multipliers saying "by per core" and if your doing a manual overclock you can change that to "by all cores".
So your choice here is that you can go with the "Gamer preset" or take and make your own overclock a bit higher.
This is a readout of what the temps are at idle for the Gamers overclock.
To go higher.
Step 1. If your deciding to go higher then you will have to make the changes to do so. Reset to default and set the AI overclock to auto and set the by all cores option.
Step 2. Go to the CPU Performance settings and change the auto setting to 45.
The 45 multiplier will be a good start since the Gamer preset went to 47 you should not have any trouble with 45. Set the Vcore to 1.4v.
The actual voltage will still say 1.14 until you save and exit and that will make the changes take effect. So at this point you can go ahead and do that and go into Windows to make sure your stable. Once you verify stability go back to te bios and change the multiplier to 47 and save and exit , go into Windows and see if the 1.4v will hold . If it does then run a stress test to verify it being stable. Then return to the bios and try for 48 on the multiplier and save and exit. If some voltage is needed at any time then add it in increments until Windows is stable. For 4.8ghz you may have to go to 1.45v on the vcore or make some changes in other parts of the overclocking section to help to get it stable. It's not always about the vcore. Asus provides some extra options to help with an overclock. The Dig + Power Control section has numerous settings to help stabilize an overclock.
For a first time over clocker you can get a really decent overclock right away with the Gamer profile. Then you can stay with that or move higher with experience.