First C3/C6 enabled overclock
4.3ghz - 4 cores
4.4 - 3
4.5 - 2
4.6 - 1 core
I call it perfect ;) It's probably not the best overclock but I am happy with it.
C3/C6 enabled OCs are easy. But you need to do core per core. If you want all 4 cores at the same frequency at 4.6 ghz for example you need to add a big amount of safety zone for the vcore.
4.6 GHz - 1.32v - 1C
1.375v-1.4v for 4 cores. I thought it was just too much.
I suggest you stay between 1.425v-1.575v for DRAM voltage. I don't like going higher. The IMC is already so fragile. And by increasing DRAM voltage you put extra stress on the IMC. I read it somewhere. But I can imagine it's true.