Before we start, check out JJ’s videos covering various aspects of the ASUS Crosshair V Formula and the ASUS 9** motherboard series:
Same drill as our Intel P67/Z68 guide, we’re going to list the important overclocking related BIOS functions and provide a concise descriptive text next to each to de-mystify their meaning and conditions of use.
Upon entering UEFI BIOS, you’ll need to head over to the AI Tweaker section to embark on any overclocking:
AMD’s 9 series chipset gets UEFI BIOS
Load Extreme OC Profile: Contains pre-set BIOS profiles to help overclock the system if you don’t wish to experiment with settings yourself. The profiles used are general fine for normal use, though may set certain voltages a little higher than absolutely necessary simply to ensure that the profiles work with a wide range of processors and memory. If you don’t plan on spending copious level of time in the BIOS fiddling with various parameters, then these profiles will help you overclock the system with minimal fuss.
OC Tuner: Our automated routine that overclocks a system based upon cooling and components. When selected the system will run a series of tests during system boot (do not be alarmed if your system reboots a few times after selecting this setting and saving and exiting BIOS – that’s normal). After the procedure is complete, you may wish to enter the operating system and run your preferred stability tests to confirm stable operation. Do bear in mind though that for compatibility purposes OC Tuner will use memory module JEDEC timing values.
CPU Ratio: Sets the CPU core multiplier ratio, which is multiplied by the “CPU Bus/PEG Frequency” setting to obtain CPU core frequency. The current and target processor speeds are shown in the top-left of the AI Tweaker menu.
AMD Turbo Core Technology: Sets the Turbo multiplier ratio. Turbo Core Technology allows the processor to ramp its core frequency to a higher level during software loading provided that the thermal design power ratings are not breached (by default).
This setting can be used to over-ride the default Turbo Core multiplier ratio (TDP permitting). The multiplier values available for this function are dependent upon the processor used. If using a manual setting that is higher than the default Turbo Ratio, care must be taken to ensure that processor core voltage is adequate enough to sustain Turbo Core frequency speeds. *To be Updated at a later date *
CPU Bus/PEG Frequency: Sets the reference clock frequency from which the processor, memory, memory controller and the HT bus are derived. Adjusting this value allows granular control over these bus frequencies which can then be offset using multiplier control of each corresponding bus to ensure that the functional limitations of a bus are not breached while overclocking the system.
PCIe Frequency: Directly sets the PCIe bus operating frequency. Manipulation of this setting is not required for most overclocking.
Memory Frequency: Sets the memory bus multiplier ratio and is used in conjunction with the value entered in the CPU/Peg Frequency setting to obtain the memory operating frequency. The range of available multipliers ratios depends upon the processor used while usage is dependant on the operational limitations of the processor and memory modules.
CPU/NB Frequency: Sets the multiplier ratio of the integrated memory controller (on the processor die) and is used in conjunction with the value entered in the CPU/Peg Frequency setting to obtain the memory controller operating frequency. The range of available multipliers ratios depends upon the processor used while usage is dependent on the operational limitations of the processor.
HT Link Speed: Sets the multiplier ratio of the HT bus and is used in conjunction with the value entered in the CPU/Peg Frequency setting to obtain HT link operating frequency. The range of available multipliers ratios depends upon the processor used (and which CPU/NB Frequency ratio is used) while usage is dependent on the operational limitations of the processor and motherboard.
CPU Spread Spectrum: Modulates the processor clock to reduce radiated noise emissions – disable for overclocking as clock modulation reduces logic sampling margins.
PCIe Spread Spectrum: Modulates the PCIe clock to reduce radiated noise emissions – disable for overclocking as clock modulation reduces logic sampling margins.
EPU Power Saving Mode: Sets the load dependant phase switching conditions; the VRM is made up of multiple phases (each phase has at least two FETs). During light-load conditions FETs can be switched off to save power – setting EPU to Enabled allows this to happen. If EPU is disabled all phases will remain on, regardless of system loading.
DRAM Timing Control: Takes us to the DRAM timing sub-menu, where primary, secondary and tertiary memory timings can be set.