6600K will not go past 4.7 GHz

uchennawork,

On behalf of Tom's Moderator Team, welcome aboard!

WildCard999 is correct. 6th Generation Core i was Intel's first 14nm (nanometer) processor. Most top out at 4.8GHz. 7th Generation is known as 14nm+ which is a more refined silicon fabrication allowing many to reach 5.0GHz. 8th Generation is 14nm++ and can reach 5.1GHz.

There is a company which is actually named "Silicon Lottery" that specializes in selling "binned" (and delided) CPU's. Binning refers to the process by which CPU's are tested and sold according to overclocking results. Silicon Lottery is highly experienced and reputable, and provides some interesting frequency and voltage statistics on their website - https://siliconlottery.com/collections/all/products/delid

Overclocking is always limited by two factors; voltage and temperature. No two processors are identical; each processor is unique in voltage tolerance, thermal behavior and overclocking potential, thus the term "silicon lottery" which is a popular buzzword known to many enthusiasts.

When tweaking your processor near it's highest overclock, keep in mind that for an increase of 100 MHz, a corresponding increase in Vcore of about 50 millivolts (0.050) is needed to maintain stability. If 70 millivolts (0.070) or more is needed for the next stable 100 MHz increase, it means your processor is overclocked beyond it's capability.

Since you're already at 4.7GHz with 1.356 Vcore, and the maximum "recommended" Vcore for 14 nanometer processors is 1.400 volts, it's unlikely that you can reach a stable 4.8GHz overclock without exceeding 1.400 volts. Without delidding, even using the H110i GTX in a normal thermal environment of 22°C (72°F), it's questionable whether your 6600K can maintain reasonable (80°C) Core temperatures at a steady 100% workload (Prime95 v26.6 Small FFT's). Higher Core temperatures can negatively impact overclocking and stability.

Remember to keep overclocking in perspective. For example, the difference between 4.7 GHz and 4.8 Ghz is less than 2.2%, which has no noticeable impact on overall system performance. It simply isn’t worth pushing your processor beyond recommended Core voltage and Core temperature limits just to squeeze out another 100 MHz.

If you'd like to learn more about Core temperatures, then read our Guide: Intel Temperature Guide - http://www.tomshardware.com/forum/id-1800828/intel-temperature-guide.html

You might find Section 8 - Overclocking And Voltage of particular interest.

Once again, welcome aboard!

CT