Asus Z170-AR Manual page 69

Ai Overclock Tuner [Auto]
This item allows you to select the CPU overclocking options to achieve the desired CPU
internal frequency. Select any of these preset overclocking configuration options:
[Auto] Loads the optimal settings for the system.
[Manual] Automatically optimizes the CPU ratio and BCLK frequency.
[XMP] If you install memory modules supporting the eXtreme Memory Profile
(XMP) Technology, choose this item to set the profiles supported by your
memory modules for optimizing the system performance.
The following item appears only when you set the Ai Overclocking Tuner to [Manual].
BCLK Frequency [100.00]
This item allows you to set the BCLK (base clock) frequency to enhance the system
performance. Use the <+> or <-> to adjust the value. The values range from 40.0 MHz
to 500.0 MHz.
We recommend you to set the value based on the CPU specification, as high BCLK
frequencies may damage the CPU permanently.
ASUS Z170-AR Series
2-17