Intel Core i7 5775C Review @ OCC
 

"That being said, Intel left some meat on the bone for the enthusiast when it came time to overclock the Core i7 5775C. A speed of 4.1GHz was not a problem for this core with nothing more than bumping the core clock multiplier to 41. Sweet and simple with nothing else needed. However, if you wanted a bit more, this chip loves to get fed a steady diet of voltage to make it happen, to a point. Up to 4.3GHz was rock solid using my 2400MHz Patriot memory kit by setting the core voltage up to 1.375v. Any higher and you could feed it voltage to get some benchmark stability, but that was it, so I stayed at 4.3GHz with a 40 cache ring ratio."

http://madshrimps.blogspot.com/2015/...eview-occ.html