As it created previously, Intel has a couple of Skylake-based CPUs with unlocked clock multipliers (the K-series SKUs). These can be overclocked by simply increasing the ratio on a Z170 motherboard. The company also made changes to its PCH that again enable BCLK-based overclocking as well.
As a result, some motherboard vendors are trying to arm their platforms with the ability to overclock non-K-series CPUs, and to make some of Intel's other chipsets overclock as well. Although these capabilities would be immensely popular among enthusiasts, there are a few problems with trying to tune multiplier-locked Skylake-based CPUs.
For instance, once the BCLK of a non-K-series processor rises above its stock 100MHz, certain power-saving features, Turbo Boost and specific instructions no longer work. Thus far, this happens on all motherboards capable of overclocking non-K-series processors, regardless of chipset. The board vendors are forced to disable those features while overclocking to ensure stability. Their loss isn't debilitating, especially since power-saving features are often disabled as part of an overclock anyways. However, we know nobody likes restrictions imposed on them forcibly.
Currently, there are only two companies with motherboards capable of overclocking non-K-series CPUs. Supermicro was first on the scene, and it also has a platform that can overclock based on a chipset other than Z170. Its C7H170-M employs the H170 PCH and is built a lot like competing Z170 boards. As of this writing, the company doesn't have any other boards capable of overclocking non-K-series CPUs.
ASRock's Shifting Position
ASRock also has non-Z170 motherboards capable of overclocking non-K-series Skylake CPUs, but they've been hit by several setbacks. ASRock initially announced “Sky OC” both as a feature for Z170 boards and as a family of overclockable non-Z170 motherboards. Thus, any product with the Sky OC feature was able to overclock non-K processors, and the boards based on chipsets other than Z170 could overclock K-series CPUs using BCLK adjustments as well.
Not long after ASRock announced these boards, the company contacted Tom’s Hardware to let us know it abandoned their development under pressure from Intel. It was also forced to remove the Sky OC feature from its Z170 motherboards.
The quote went a little something like, “ASRock has decided to remove SKY OC technology from these motherboards’ feature lists since it is not compliant with Intel Skylake CPU specifications.”
We expected that to be the end of ASRock’s venture into overclocking non-K-series CPUs and overclockable non-Z170 chipsets, but then the company released its cancelled C232 Fatal1ty E3V5 Performance Gaming/OC board. It also announced its new “Hyper” family of non-Z170 motherboards able to overclock non-K-series processors using BCLK manipulation. Currently, the C232 Fatal1ty E3V5 Performance Gaming/OC is the only one of these boards available for sale online. The others may materialize in time, but it's also possible that Intel again applied pressure to stop their introduction.
Fallen Attempts At Non-K OC
Biostar tried to arm its motherboards with the ability to overclock non-K CPUs using a BIOS update for its Z170 boards. The approach was similar to the way ASRock enabled Sky OC. And like ASRock, Biostar removed the feature through another BIOS build that included new microcode from Intel.
According to a representative, “Intel regularly issues updates for our processors which our partners voluntarily incorporate into their BIOS. The latest update provided to partners includes, among other things, code that aligns with the position that we do not recommend overclocking processors that have not been designed to do so. Additionally, Intel does not warranty the operation of the processor beyond its specifications.”
Supermicro does not appear to have applied this update to its C7H170-M motherboard, but that could be just a matter of time. Technically, all of these boards are still able to overclock non-K CPUs, though to do so requires an outdated BIOS that might have other issues. This makes unsanctioned overclocking essentially dead.