GIGABYTE Z270 Extreme Overclocking Guide

The GIGABYTE OC team prepared a GIGABYTE Z270 Kaby Lake extreme overclocking guide for those who wish to get the most out of their Kaby Lake-based processors. The guide was originally published by GIGABYTE and is shared at with explicit permission.

The following guide will show you how to do achieve the highest frequencies and performance using liquid nitrogen. We recommend you use the GIGABYTE Z270X-Gaming SOC or GIGABYTE Z270N-Gaming 5 if you wish to experiment with this type of extreme overclocking.

In this guide we use the Intel Core i7-7700K and the GIGABYTE Z270X-Gaming SOC. Similar settings can be used with other Intel K-series CPUs or on the GIGABYTE Z270N-Gaming 5.


GIGABYTE Z270 Advanced OC Guide

For the basic settings please follow the Advanced Guide (disable features etc). You can find this part of the guide in the magazine posted on Joomla:


Enable Single BIOS Mode

Make sure you turn it ON (position 2). This switch will disable Dual bios mode in case it triggers a bios switch or update due to OC fail.

GIGABYTE Z270 Single BIOS mode

Preparing Your CPU for Extreme Overclocking

Like extreme OCing on previous generation CPUs you need to delid your processor (see Page 16 or the advanced overclocking guide). By delidding your processor you will be able to get higher frequencies out of your chip by increasing the degree of coldness your CPU can handle (preventing cold bug). You can use any delidding tool available on the market. We’re using der8auer’s tool and it works well.

We prefer to replace the paste on the die of the CPU every single time we use it. It works better for us. Remember to apply enough paste on the die.

Mount your CPU pot correctly without tightening it too much. From our experience sometimes when we overtighten it we find ourselves placing it carelessly which affects our CB.

Adjust Voltages

CPU Voltage Settings:

GIGABYTE Z270 CPU Voltage Settings

CPU Vcore: For extreme cooling (LN2) you’re aiming for 1.85-1.90V to max out your CPU. There are CPUs that can obtain higher frequencies using higher voltages but 1.85V is a good starting point.

CPU VCCIO and CPU System Agent: These settings will mainly aid you in memory overclocking. A setting of up to 1.4V on both maxes out most DRAM. We suggest you start slowly from 1.3V on both and find the optimum value for your DRAM/CPU.

VCC Substained: Set this to 1.45-1.55V. Start from 1.45V and check if your CPU needs more. If you’re getting random freezes at high clocks raise it to a higher value.

VCCPLL: Make sure you have iGPU disabled before you do this as it might kill your iGPU otherwise. Make sure you are using a discrete graphics cards. 1.8V should eliminate CB in a CPU. From our experience you don’t need higher than that. If you’re limited only to 1.5V then you need an X version bios (available in “Overclocking Software” section).

VCCPLL OC: You’re looking at values around 2.0V. It helps if you’re hitting the CB earlier than you should (-130C or so). Some CPUs need higher but 2.0V is a good starting value. Keep this value under 3.0V or you might degrade your CPU.

VCCVTT: 1.65V should work well for most of the CPUs. If you’re getting random freezes at high clocks try to raise it. Keep this under 1.75V or damage could be done to your CPU even when using LN2.

VCCDMI_PEG: This setting is used to stabilize your 3D VGA performance.
We always set it at 1.4V and then raise it when it’s needed. Depending on how your VGA behaves, up to 1.85V is fine. Make sure you raise VCCIO along with VCCDMI_PEG, set VCCIO anywhere from 1.25V to 1.4V otherwise your CPU might not boot.

For PCI-E 2.0 2D and 3D benchmarks set it to a value of at least 1.4V to avoid CB. If you’re using a PCI-e 3.0 VGA then you can choose to use Nvidia PowerMizer Manager (nvpm manager) or in the BIOS set a high VCCDMI_PEG (1.8V+).

If you’re using a PCI-E slot from PCH then VCCDMI_PEG doesn’t affect that slot.

CPU Core PLL Overvoltage (+mV): This setting depends on your CPU. Start without it and try to raise it to see if it helps your CPU. Values up to 285mV work ok on LN2. (Default value is 0.9V)

PCH Core: You should raise this setting together with VCCVTT. We always set it at 1.12-1.14V. If your system reboots and it goes to code C5 with a blank debug LED then raise this value.

CPU Vcore Loadline Calibration
: Even though “Turbo” should work just fine we prefer to set it at “Extreme” just to be safe.

GIGABYTE Z270 CPU Vcore Loadline Calibration

Just to be safe we prefer to always make 2 profiles. The first one is without these voltage settings and the second one is with them. We then cool the CPU down to -70C or so and then load the second profile.

Find Your CB (Cold Bug) and CBB (Cold Boot Bug) Temperatures

If you’re not an experienced extreme overclocker we suggest you to spend the time to find the CB and CBB of your CPU. Once you find them you will be able to eliminate CB and CBB off of a list of issues that may be hindering your overclock.

Cold Bug is the lowest temperature your CPU can operate at. Cold Boot Bug is the lowest temperature your CPU be at and still boot. From our experience with the 7th gen CPUs, we’ve seen that CB and CBB are very similar to the previous 6th gen CPUs. CBB is mostly CPU specific and it is approximately around -130C. Some CPUs may be able to boot at -120C and some at -135C. CB on all the CPUs we’ve tried are the same—you can go full pot (-190C).

Adjust Frequencies + Some Tips

CPU frequencies range from 6.4 to 6.9 and maybe even higher for HWBOT Prime. Good CPUs can do 6700+ with around 1.8V. Some CPUs stop scaling at around 1.8-1.85V but some can go up to 1.9+.

Some good news—from our observations we’ve seen that average next-gen retail Intel CPUs can clock as high as engineering samples.

Uncore uses CPU Vcore voltage. If you want to raise Uncore frequency you might want to raise CPU Vcore voltage. 6700 Mhz Uncore worked for us on SuperPi 32M.

If you’re hitting lower frequencies (i.e 6 Ghz) make sure your CPU mounting is good.

Compared to a Gaming 7 motherboard the same CPU could only clock up to 6.2 Ghz, when on Gaming SOC due to its extra voltage settings it was able to do 6.7 Ghz. We found no difference between the motherboards when doing standard overclocking on air or water.


GIGABYTE Z270 OC Troubleshooting

Potential issue: previously stable frequencies are now unstable

Make sure you have a stable mount when you are overclocking. You will find that once you start to push high frequencies and volts that your paste may not work correctly and your CPU can become unstable at previously stable frequencies. The best way to OC is to use a staggered approach where you start with a 5, 5.5, 6 and 6.5 Ghz profiles with specific volts and temp ranges. If you crash at any stage, you probably “lost your mount”. Essentially your paste snapped and is not conducting heat properly between the CPU HS and CPU pot. One way you can detect this is with a delta probe (keep one temperature probe on HS and second on CPU pot).

A quick way to fix this is to turn off the system and heat it up to -25C and then quickly bring back temps down to cold and start again. 90% of the time, you will be able to get high clocks again but may not be able to get max clocks until full paste remount (full CPU pot warm up, paste replacement etc). We always prefer the full paste remount since it works better for us. If you see after some time that you start losing Mhz then it’s time to dry out your system and give it some time to recover and start again.


Potential issue: a few codes you might see on the diagnostic LED during overclocking

02, 04, and 06: To solve the issue turn off your PSU and wait a few seconds and let the power drain from your system. Then switch it back on and turn on your system.

C4: To solve the issue press the restart button on your motherboard.

GIGABYTE Z270 Overclocking Software and Legacy O/S Support

GIGABYTE Tweak launcher (GTL) / MemoryTweak:

GIGABYTE Tweak launcher is an app to overclock in Windows. Below are things you should watch out for when using the application.

  • We prefer to un-tick all the boxes (“Clear all check” option) and tick only those which we use the most (Cores and VCore) each time we start the app.
  • Un-tick PLL OC when you have it higher than 1.75V in the BIOS because it causes freezes when you re-apply it from GTL.
  • For some Gaming motherboards which are missing the VCCPLL option in the BIOS you can apply it from here.

GIGABYTE Z270 TweakLauncher

Link to GIGABYTE TweakLauncher:


MemoryTweak lets us monitor our memory timings in Windows. It works on most of the motherboards we’ve tried including Z170 models. You can open it 2 or more times so you have all the timings shown.

GIGABYTE Z270 MemoryTweak

If you experience any bugs with MemoryTweak let us know in the comments below.

Link to MemoryTweak:


BIOS “x”

Here is the “x” bios version for the GIGABYTE Z270X-GamingSOC that allows you to select higher voltage settings.


Legacy O/S Support

Because some benchmarks perform better on older OSes you may want to run them even though they are not officially supported by Intel. Below are things you need to do to get them working.

For both XP and Windows 7 you might experience a laggy cursor. To remedy this you’ll want to buy a PCI Express USB Adapter. We recommend you to buy a NEC USB Adapter with a D720200F1 IC because we can confirm that it works.

How to boot into XP: Connect your boot hard drive or SSD to the following two ports highlighted below.



Leave a Reply to Robertlet Cancel reply

Your email address will not be published. Required fields are marked *