Z97 Pro 4


ASRock Z97 Pro 4 OC-Guide

This guide is an example how to overclock your CPU using an ASRock Pro 4 motherboard. This guide is following the instructions given in the general Intel Haswell OC-Guide.

This example was done using a i5-4690K CPU. You can apply the same settings if you use any other K-Suffix CPU such as 4770K or 4790K.


  • ASRock Z97 Pro 4
  • Intel Core i5-4690K
  • 2 x 4 GB DDR3 2933 C12
  • Phanteks PH-TC14PC CPU cooler
  • Sea Sonic Platinum Series 1200 W


  • Windows 7 x64 Service Pack 1
  • CPU-Z
  • Core Temp
  • Prime95

You can download the required software here:

CPU-Z 1.71 Setup EN
1.50 MB | 2179 downloads
CoreTemp 1.0 RC6
717.26 KB | 9935 downloads
Prime 95 v28.5 64-Bit
15.39 MB | 31834 downloads
Prime 95 v28.5 32-Bit
4.13 MB | 1201 downloads


Basic video OC-Guide for overclocking from 3.5 GHz to 4.0 GHz:


BIOS screenshots of the basic OC from 3.5 to 4.0 GHz:

20141220223850 20141220223907 20141220223916 20141220223921

20141220223926 20141220223933 20141220224002 20141220223840

Please keep in mind that the voltages for your CPU might differ from this example. If your CPU core is not stable at these settings and you don’t exceed 90 °C core temperature, try to raise the CPU core voltage.


Important BIOS Settings explained:


PCIe PLL Selection

LC PLL works best for low/stock clock BCLK of 100 MHz. LC PLL is and inductor capacitor based oscillator for low noise but only for a low range. If you overclock the BCLK, change to SB PLL or simply leave on auto.


Filter PLL

This is only needed for very high BCLK of over ~167 MHz. Just leave this setting on auto.


BCLK Frequency

The Base CLocK of your system. This frequency is tied to the PCIe clock and the DMI bus. High frequencies can cause your system to be unstable. Use the BCLK/CPU Strap for high BCLKs. Raising the BCLK will also raise the CPU core, ring and RAM frequency.


CPU Ratio

You can choose whether you want all cores to be clocked at the same level (All Cores) or clock them separately. I recommend to use all cores to get the maximum performance.


All Core

This setting will change the CPU multiplier of your system. If you run a BCLK of 100 MHz and select 37 here, your CPU will run at 3700 MHz core frequency.


CPU Cache Ratio

This will set the CPU cache/ring ratio. If you run a BCLK of 100 MHz and select 35 here, your CPU cache/ring will run at 3500 MHz.


Internal PLL Overvoltage

This can improve the overclock-ability of some CPUs. I recommend to set this to enabled.


DRAM Frequency

The DRAM Frequency is the result of the BCLK and an additional multiplier. E.g. 100 MHz BCLK and 18.66 multi will result in 1866 MHz RAM frequency. Higher than 2933 MHz usually doesn’t work. If you want to achieve higher memory frequencies, you have to use a different BCLK strap.


CPU OC Fixed Mode

Automated overclocking. I recommend to not use this feature.


CPU Vcore Voltage Mode

Select “Override Mode” to adjust the CPU voltage. This is the core voltage of your CPU. Increase this voltage if you want to achieve higher core clocks. Usually more than 1,35 Volt is not recommended for daily use.


CPU Cache Voltage

Select “Override Mode” to adjust the CPU cache voltage. This is the cache/ring voltage of your CPU. Increase this voltage if you want to achieve higher core clocks. Usually more than 1,15 Volt is not recommended for daily use.


System Agent Voltage Offset

This voltage is important to run high memory clocks. Stock is 0.85 Volt and usually you don’t need more than 1.00 Volt (+0.15 Volt) for 24/7 systems.


CPU Digital IO Voltage Offset

This voltage also helps for memory overclocking. Stock voltage is about 1.0 Volt. More than 1.15 Volt (+0.15 Volt) is not recommended for daily use.


CPU Analog IO Voltage Offset

This voltage also helps for memory overclocking. Stock voltage is about 1.0 Volt. More than 1.15 Volt (+ 0.15 Volt) is not recommended for daily use.


CPU Input Voltage

Select “Fixed Mode” to adjust the CPU Input Voltage. CPU Input Voltage is the voltage delivered from the mainboard to the CPU. All other voltages such as CPU Core voltage will be changed from the Input Voltage in the CPU internally. Stock Value is 1.80 Volt. Sometimes a lower voltage such as 1.7 Volt can improve the overclocking. You can use up to 2.1 Volt for daily use.


DRAM Voltage

The DRAM Voltage is the Voltage of your memory. Check the memory modules for the specified voltage. Most are between 1.35 and 1.5 Volt. The official limit according to Intel is 1.5 Volt, however 1.65 Volt modules are no problem at all according to my testing.


PCH 1.05V Voltage

This is the chipset voltage and doesn’t have to be changed since it doesn’t help in any way.


Spread Spectrum

The spread spectrum reduces signal spikes. However it will leade to a worse overclocking so always disable this setting.


Intel SpeedStep Technology

Intel SpeedStep will downclock your CPU in idle to save energy. I recommend to disable this feature because you only save about 2-5 W, but it can cause your system to be unstable when overclocking.


Turbo Mode

Leave this setting enabled using ASRock motherboards. Otherwise you will not be able to increase your CPU multiplier.


CPU C-States

The C-States are another energy saving option which I recommend to disable for maximum overclocking. However you can keep them enabled for moderate overclocking.


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  • cRckR

    Thanks for the cheat sheet dood ..I find some of you voltages to be a little conservative based on the other articles I have read but you do a great job of explaining them

    • der8auer

      Thanks 🙂 They are indeed conservative. Some users are just not very experienced and may not have a good CPU cooler as well. So this is just to stay safe. If the want to clock higher or use higher voltages they have to read a full guide 🙂

      • cRckR

        Let’s start with my Rig …….not BS this is really mine…not bragging..it is what it is.not the best in the world but no slouch either .I totally need help getting a solid overclock on it ..your post seems well thought out and after reading hundreds of pages… I think …if you are willing..feel free to tell me to fuck off…I want to collaborate with you to get a solid OC. I am an old school gamer Overclocker and this is my first new build since 2007. Plenty of upgrades but nothing totally new….this took me a year to build…very careful part choices….made a few mistakes…did not know about the 840 EVO read/write degradation… but will be a hassle to update bios when the fix it.. my fan controller functions well but the quality is crap not a total game changer… The Jury is still out on the board. . I will admit that I am totally lost when it comes to Z97..with the settings I have I can probably get a stable 4.7 to 4.8 OC ..I want 5.0 or higher..most of the posts I read are change 3 or 4 settings and poof you are there ..not worth doing..I built a solid OC machine..I have great airflow…tons of fans sounds like an aircraft lol ….I want a 24/7 OC but my rig only runs 3 days a week ..I don’t run it during the week….fri/sat/sun only……also my for some tweaking but I do not plan to use software to OC … I have been messing around with the OC genie..gear 1 work fine…4.4..BS OC…but low Voltage..gear 2 pumps it up to 4.7 but it is unstable.. anywho that’s my rant let me know if you wanna help
        MSI Z97-GD65

        i7 4790k
        16GB GSKILL Trident 2400MHZ

        4 x 250GB Samsung 840 EVO Raid 0
        2 X MSI 970 GTX
        Corsair AX860 PSU
        Fractal Designs S36 360mm AIO Water Cooler Push/Pull
        Corsair 760T Graphite Full Tower
        Lamptron FC5 6 Channel V3 Fan Controller

        I based the following settings from the MSI Z87-GD45 from this guide I noticed some differences from my board but a lot is the same…


        Base Clock 100
        Base Clock Strap — Auto
        OCIE PLL — SB-PLL
        Filter PLL — Auto
        Adjust CPU Ratio — Auto
        Adjusted CPU Ratio —- 3400MHz
        EIST —– Enabled
        Intel Turbo Boost —- Enabled
        Enhanced Turbo —– Enabled
        Adjust Ring Ratio — 41
        Adjusted Ring Ratio —- 4100 MHz
        DRAM Reference Clock —- Auto
        DRAM Ratio —— Auto
        Adjusted DRAM Frequency –— 2400MHz

        Extreme Memory Profile — Profile 1
        DDR3 2400 MHZ ??? dony know my timings off hand

        Digital Power ?? You suggest 1-1.15 set to auto in my example called power not IO voltage offset probably due to auto setting…MSI advises 1.1-1.25
        ACCIN Voltage 1.800 What the hell is this
        CPU Core Voltage mode 1.250 to 1.4
        CPU Core offset mode +
        CPU core voltage offset 0.005
        CPU IO Analog Offset more all set to auto you recommend 1.0 to 1.15 MSI recommends 1.1-1.25
        Internal VR OVP OCP AUTO
        Intenal VR Efficiency Mode DIsabled
        DRAM Voltage 1.5 ??
        PCH Voltage 1.070
        PCH 1.5 Voltage 1.520

        Active Processor cores all
        Limit CPUID Maximum Disabled
        Execute Disable Bit Enable
        Intel Virtualization Tech Enabled
        Hardware Prefetcher enabled enabled
        Adjacent Cache line Prefetch Enabled
        Intel Adaptive Thermal Monitor Enabled Intel C-state Auto ..you say disable…my bios has like 4 or 5 c-states not sure wtf to do
        C1E support Disabled
        Package C-state limit disabled
        Long duration power limit auto
        Long duration maintained Auto
        Short duration Power limit Auto
        Current CPU limit Auto

  • Dan

    Hi there. I have a couple of questions.

    1. When I go into Bios my v core is at +0.990V instead of your +1.022V should I follow what you did and bump it up +100 to 1.090V, or go to 1.122V. (Same cpu and mobo)

    2. I don’t have the xmp option so I’m guessing my rams not compatible with xmp, would it be OK to just leave as is for now until I find out what ram it is (waiting for reply from the people that built my pc)

    Thanks a bunch!

  • cRckR

    Well after many weeks of waiting I finally made the time and dove in and made it to 4.8 stable 33c idle 80c max…been using Intel Tuning Utility Stress test not Prime 95 but will give prime a go ….at the top of your safe range …..got a few more options in my bios you don’t talk about…sorry to jack your thread..know this is all about Asrock I was just so excited to find a Z97 specific page that I went overboard..Still would appreciate some input if you have the time in this forum or by email.or you could always start a MSI thread I have setting to contribute

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