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
- Core Temp
You can download the required software here:
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:
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.
This is only needed for very high BCLK of over ~167 MHz. Just leave this setting on auto.
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.
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.
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.
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.
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.
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.
Leave this setting enabled using ASRock motherboards. Otherwise you will not be able to increase your CPU multiplier.
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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