The Problem With Overclocking On Non-Z170 Chipsets

When it was discovered that all of Intel’s 6th Gen (Skylake) Core processors could be overclocked using simple base clock adjustments, we were told by Asrock that it might be possible to overclock these processors using other motherboard chipsets besides Z170. Super Micro has had an H170 motherboard on the market for several weeks now that is capable of performing base clock overclocks, and Asrock announced at CES that it will have four motherboards capable of this feat, as well.

Although increasing the clock speed on the processor should increase its performance, there are some serious problems that come from enabling overclocking with non-Z170 chipsets, and users will need to carefully weigh the pros and cons of these motherboards before buying.

Modding A Chipset To OC

With the exception of the Z170 PCH, chipsets created by Intel for the LGA1151 socket often don’t give users voltage control of several key pieces of hardware, such as the CPU, and lack several other overclocking-related features such as multiplier control, base clock control, Vdroop, load-line calibration and others. This is partially because these features are not supported on non-overclocking chipsets by design, but it’s mostly because many of these features aren’t particularly useful if you can’t overclock, so motherboard OEMs don't waste their resources implementing them.

In order to enable overclocking on a chipset like H170 or B150, hardware modifications and firmware support for these features must be added. Motherboard OEMs can make these changes, but it has the side effect of disabling several other features. Asus, Asrock and MSI told us that non-Z170 chipsets modified to enable overclocking will lose Hyper-Threading support and will be unable to use C-states to reduce voltage and power consumption when the system is idling. 

Because motherboards using these modified chipsets are focused on overclocking, losing the ability to use C-states isn't a major issue, as overclockers often disable power saving features in order to obtain higher overclocks. Losing Hyper-Threading support, however, is a huge problem, as Core i3, Core i7 and Hyper-Threaded Xeon CPUs will lose a significant amount of performance in multi-threaded workloads, which defeats the purpose of overclocking in the first place.

Taking these problems into consideration, motherboard OEMs have responded differently to the idea of developing non-Z170 overclocking motherboards. Before we go over how the various OEMs are reacting to this concept, there are a few important points that need made.

First, the H170, H110, B150, Q170, Q150, C232 and C236 chipsets have Hyper-Threading and C-state support, but the hardware alterations required to give them overclocking features permanently disable Hyper-Threading and C-states regardless if you are actually overclocking or not, and it doesn’t matter which CPU you use.

So, if you aren't going to overclock, you will want to choose a different motherboard with a non-modified chipset. Second, although modified chipsets capable of overclocking will lose these features, it is an issue with the motherboard and not the CPU. Non-K CPUs overclocked with a Z170 chipset motherboard will still have full support for C-states and Hyper-Threading.

Asus

In addition to the problems mentioned above, Asus stated that motherboards using modified chipsets to enable overclocking will also lose support for some instruction sets, and any non-Z170 boards designed to overclock would have significant reliability issues, resulting in numerous CPU and motherboard failures.

An Asus representative told us that to develop and sell these motherboards to its users would therefore damage its standing among PC enthusiasts. Asus made it clear that it felt producing motherboards with modified chipsets would be a huge liability, and that it would be irresponsible and a disservice to its loyal customers. Suffice it to say that you should not expect to see any motherboards designed to overclock from Asus on the LGA1151 socket with the exception of the enthusiast Z170-chipset boards.

ASRock

Asrock took the opposite approach by already announcing two H170 motherboards, one B150 motherboard and one C232 chipset motherboard with overclocking features. Asrock said that these systems would lose support only for Turbo Boost and C-states, and although it was unable to resolve these issues, Asrock felt that it should release these motherboards because customers want them.

Gigabyte

Gigabyte didn't have much to say on this topic, and it did not say if it would release motherboards with these modified chipsets or not.

MSI

When we asked MSI about developing non-Z170 overclocking motherboards, the company expressed concern about the reliability and loss of features that comes with modifying those chipsets. The company said that it doesn't have any current plans to release motherboards with overclocking features outside of its Z170 chipset systems, but it is currently testing the idea and might release some non-Z170 motherboards designed to overclock if it sees strong demand from consumers.

Super Micro Has An Edge

Unlike the other motherboard OEMs we spoke to, Super Micro discovered a way to enable overclocking on an H170 chipset without losing Hyper-Threading support. Super Micro said it was actually the first motherboard OEM to develop a motherboard with a non-Z170 chipset capable of overclocking Skylake CPUs. Its C7H170-M H170 motherboard has been available on the market for roughly three weeks now.

The C7H170-M is priced comparably to Z170 motherboards, but it proves that overclocking Hyper-Threaded CPUs on an H170 motherboard is possible without losing the extra CPU threads, and we will likely see more of these boards from Super Micro in the future. The system still loses support for C-states, but as we stated above, many enthusiasts will consider this an an acceptable loss, as they would disable power saving features anyway.

Choose Your Motherboard Carefully

Because hardware modifications are required to enable overclocking on non-Z170 chipsets, unless a motherboard OEM explicitly states that the system has this feature, you should not expect overclocking capabilities on non-Z170 chipsets. If you are set on overclocking and don't want a Z170 chipset, make sure that you choose your next motherboard carefully, as pairing the wrong motherboard and CPU together may turn your $300 Core i7 into a $200 Core i5 and significantly reduce your overall system performance.

Update, 1/13/16, 10:45am PT: There was a miscommunication between us and Asrock about what was disabled on its non-Z170 motherboards with overclocking features, and we have posted a new article covering these boards.

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Michael Justin Allen Sexton is a Contributing Writer for Tom's Hardware US. He covers hardware component news, specializing in CPUs and motherboards.
  • Gam3r01
    Unless these specially designed motherboards are still at or close to the same price as their normal counterparts you might as well go with Z170. Not just for the OCing, but for all the extra features.
    Reply
  • Darkbreeze
    That's wrong. It's all wrong. You got it all wrong. That's not how it works at all.

    Just kidding. I figured I'd say it before one of the article terrorists comes along and does. Preemptive contrarianism. Now they have no reason to do so. Seriously, good to know. Thanks for the info.
    Reply
  • Gam3r01
    My main question is why did it take this long for the disable of hyperthreading to surface when doing this? Surely someone noticed it earlier on.
    Reply
  • Darkbreeze
    Because there weren't any boards specifically designed for this purpose yet, on chipsets other than Z170. Normal H170, B150 and other chipset boards can't overclock the locked chips like the ones specifically designed for it. Really, it's kind of ridiculous to have to "design" an overclocking board for a locked chip. If you can "do" it, on non-Z hardware without having to invest significant resources into developing a new product that will require it to be more expensive than it's incapable siblings, then great. Otherwise, you might just as well get an low end Z board.
    Reply
  • IInuyasha74
    17291865 said:
    My main question is why did it take this long for the disable of hyperthreading to surface when doing this? Surely someone noticed it earlier on.

    This is a good question, and I have an answer for you. As of right now, there are only five non-Z170 LGA1151 motherboards that have been announced and are capable of overclocking. Four of the motherboards are from ASRock, and aren't available for purchase yet.

    Then there is the one motherboard from Super Micro that has been out on the market, but Super Micro did not reveal that the motherboard was capable of overclocking CPUs until earlier this week at CES. There were rumors that it was able to be overclock CPUs, because Super Micro sent the motherboard to an overclocker who competes in overclocking competitions and has set world overclocking records before to have him test out the motherboard and reported that it was capable of overclocking, but we weren't able to confirm his story until now. Others using the motherboard likely didn't expect to be able to overclock and thus didn't try to even if they noticed the base clock option available. Even if they did, because the Super Micro board doesn't disable Hyper-Threading, just C-states, anyone owning the motherboard could have easily overlooked that the board wasn't using C-state modes. I witnessed this first-hand at CES a few days ago, and confirmed this info with several companies over the week, which is the only reason we are aware of it now. That is why you are reading about it on Tom's Hardware first, hard work and journalism, getting you this out before anyone really has a chance to learn it the hard way. :)
    Reply
  • IInuyasha74
    17291828 said:
    That's wrong. It's all wrong. You got it all wrong. That's not how it works at all.

    Just kidding. I figured I'd say it before one of the article terrorists comes along and does. Preemptive contrarianism. Now they have no reason to do so. Seriously, good to know. Thanks for the info.

    Haha well glad you enjoyed the post. Lot of work went into this one, so feel free to spread this around to anyone asking about it :)
    Reply
  • Gam3r01
    Ah, thanks for clearing that up. Makes a lot more sense since nobody was thinking to look for it.
    Reply
  • TJ Hooker
    Most of these drawbacks also exist when over clocking non-k cpus on Z170 boards, i.e. loss of c-states and avx instructions (what I'm guessing Asus is referring to when they mention losing "some" instructions sets). Loss of HT is new though, and probably the most troubling.
    Reply
  • killerchickens
    Nice article, I hope you keep it up to date.:)
    Reply
  • IInuyasha74
    17291962 said:
    Most of these drawbacks also exist when over clocking non-k cpus on Z170 boards, i.e. loss of c-states and avx instructions (what I'm guessing Asus is referring to when they mention losing "some" instructions sets). Loss of HT is new though, and probably the most troubling.

    You don't lose AVX instruction support or the ability to use c-states when overclocking on a Z170 motherboard.
    Reply