Options are “Auto”, “By All Cores” and “By Per Core”. A description of these settings is provided in the right-hand column of the UEFI BIOS and can be seen when the Turbo Ratio setting is selected.
By All Cores: This sets the CPU core frequency multiplier; multiplied by BCLK to give the target CPU frequency (under full load conditions if SpeedStep is active). “Auto” = stock CPU multiplier Ratio used. Manual numerical entry of the desired Turbo Ratio is accepted.
Per Core: Allows setting the maximum Turbo multiplier of each physical processor core.