User Manual
18
PRIME X399-A BIOS Manual
Custom CPU Core Ratio
This item allows you to set a custom CPU core ratio. The CPU core ratio is calculated with
the formula: 2 * FID / DID. Conguration options: [Auto] [Manual]
The following items appear only when you set the Custom CPU Core Ratio to [Manual].
FID
This item allows you to set the core frequency multiplier. Use the <+> or <-> to adjust
the value.
DID
This item allows you to set the core frequency divisor. Use the <+> or <-> to adjust the
value.
Overclocking Enhancement
[Auto] Automatically loads the optimal settings for the system.
[Enabled] This item allows you to maximize the oveclocking performance optimized
by ASUS core ratio settings.
[Disabled] This item allows you to set to default core ratio settings.
Performance Bias
This item allows you to set different values that may help different software’s performance.
Conguration options: [Auto] [None] [CB15] [Aida/Geekbench] [CB11.5]
Memory Frequency
This item allows you to set the memory operating frequency. The congurable options vary
with the BCLK (base clock) frequency setting. Select the auto mode to apply the optimized
setting. Conguration options: [Auto] [DDR4-1333MHz] - [DDR4-4000MHz]
Core Performance Boost
This item allows you to automatically overclock the CPU and DRAM to enhance system
performance. Conguration options: [Auto] [Enabled] [Disabled]
SMT Mode
This item allows you to enable or disable simultaneous multi-threading. Conguration options:
[Auto] [Enabled] [Disabled]
Spread Spectrum
This item allows you to enable or disable CPU Spread Spectrum. Conguration options:
[Auto] [Enabled] [Disabled]
EPU Power Saving Mode
The ASUS EPU (Energy Processing Unit) sets the CPU in its minimum power consumption
settings. Enabling this item will apply lower CPU Core/Cache Voltage and help save energy
consumption. Set this item to disabled if you are over clocking the system. Conguration
options: [Disabled] [Enabled]