You got it wrong, this can only be done with skylake processors NOT "Sandy Bridge" and "Ivy Bridge" generation. BLCK is tied to the PCIe / DMI (in your case) which limits you to something like 103 blck before coming unstable, even that might be too high.
What i meant by flashing bios is AFTER you get "k" model cpu like 4770k or 4790k which is supported by that motherboard. Anything above v2.00 wont support overclocking even a "k" model cpu, which is why you need earlier version. Might be the v1.90 or you need to go even older, search it up.
was told this on another forum