You should first overclock processor and check stability test while RAM is on default settings, 1333MHz...
When you find ideal clock for you, than you should increase RAM speed. It's possible to show error because tight latency, or to higher frequency.
I do on that way, I have very nice i7-3770K stable on 4.5GHz on 1200V... That's still strong and very nice platform...
For me better than Sandy and than Haswell. Sandy was nice for OC because better heat transfer and less temperature, but platform was not better overclocked than Ivy, mybe 100MHz avarege... but Ivy had other better features, more important almost same as Haswell but better overclocker... Haswell only 4790K keeping on 4.5GHz... I'm sorry because I didn't keep Ivy one year more, because platform is still very strong after 3 year, overclocked very close 4790K, I boought litterary 1st month after launch, but I didn't want to miss such good chance as X99 and 5820K 6 cores... iF Intel give all processors with 40 lanes next time platform will cost much more, and Broadwell go up to 650$...
and I found 5820K almost as i5-4690K... Now at least I can get some nice money for Z77 platform, If I wait more, price will go down when DDR4 become standard everywhere.