Apparently, CPUs also seem to have a burn-in time as well - or at least Haswell does. Despite being capable of running at a respectable 4.6GHz, my Intel Core i7 4790K CPU managed to crash the system with a BSOD on last Friday while transcoding a video. It was a BSOD 124 which suggests the Vcore needed to be raised a notch, however as it was already reaching the limits of the Noctua NH-U12S cooler’s cooling capacity, I defaulted. There were instances where the CPU core temps would touch 90C while using Handbrake at those settings. That is terrible.
Hence, I decided to drop the multiplier one notch and settle with a clock speed of 4.5GHz. 4.5GHz could absolutely be considered subpar when it comes to Devil's Canyon which many believed would reach 5GHz effortlessly. At least in my case, temperature issues are unavoidable due to the size of the chassis.
Lowering the multiplier allowed me to reduce the Vcore from 1.26V (which was inadequate to begin with) to 1.21V. Even though the reduction seems miniscule, it resulted in a massive 10C drop in temps while running Handbrake! That’s Haswell for you.
While I care less about extending the lifespan of the CPU as I am a frequent upgrader, the ability to run the fans lower resulted in a vastly comprehensible reduction in fan noise. Despite the reviewers saying that the NH-U12S is dead silent, I could easily hear it at full fan speed, perhaps because the case was much closer to ear. However, the biggest improvement came from the speed drop of the main intake fan, the 180mm Silverstone Air Penetrator fan which is installed on top of the case.
The onboard fan controller on my Asus Maximus VII Gene board, which I use to power up the fans and control them, has one issue. It would make the fans rotate at their maximum speed once the CPU temperature (not the core temperature which is about 10C more) exceeds 75C, which I believe is in place as a safeguard. There is no way to bypass this limitation unless you use low-noise adapters. At full speed, the 180mm air penetrator is noticeably loud though, it is intolerable as a high-pitched noise. I am in the opinion that noise is indicative of quality of a PC build.
So there it is. 4.5GHz; an underwhelming overclock especially when the CPU would automatically boost to 4.2GHz is thermals are not restrictive.