I'm using the i5-4690k and I'm new to Overclocking. I found this page on anandtech thats supposed to be stable numbers...
http://www.anandtech.com/show/8227/devils-canyon-review-intel-core-i7-4790k-and-i5-4690k/2
I currently have multiplier set to 43 and cpu core voltage manually at 1.125...