Since the past month, OCaholic digged up each and every Haswell CPU from the CPU-Z database. It looks like if they keep on exploring they just might find a Broadwell processor there somewhere as well. After revealing a Core i7-4770K being overclocked to 7.01 GHz, they have yet again found another validation which shows an Intel Core i7-4770K overclocked to 5 GHz using just 0.9v.
It is astonishing to see the overclocking ability of Haswell processors compared to Ivy bridge. Core i7-3770K takes around 1.4-1.5v to be fully stabilize at 5 GHz. We are not sure whether this 5 GHz overclock is stable or was just enough to boot into Windows and validate. Lets assume that this was stable enough to validate the score, comparing it with Core i7-3770K its still approximately 0.35v less required to validate an overclock.
This means that Haswell processors require 40% less voltage for overclock compared to Ivy Bridge processors. Less voltage results in less heat and temperatures, although this was not the case with Ivy Bridge due to the low quality TIM used but we believe Intel has learnt its lesson and will improve on that. 5 GHz on air was made possible through Sandy Bridge processors, Ivy Bridge further improved the overclocking ability of the processors and now Haswell is one step ahead of the previous generations.
ASRock Z87 Extreme4 motherboard along with TeamGroup 4GB 1333 MHz DDR3 memory and Windows 7 x86 were part of the test platform. Extreme4 is a budget motherboard with good overclocking features and a nice price:performance ratio. The only aspect remains is the heat, if its under control at 5 GHz then it might be possible to break the 5.5 GHz or even 6 GHz barrier on air or with closed-loop water cooling kits.