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AMD Overclocking Terminology FAQ
This Terminology FAQ will cover some of the basics when overclocking AMD based CPU's from the Ryzen series. This covers the Zen, Zen+ and Zen 2 architectures and all products stemming from those architectures. Going over some of the basics of BIOS settings and what a function is or why it should be turned on or off and under what condition(s). These settings will vary from motherboard and CPU as well as the degree at which they can set in the BIOS.
What is a VRM?
VRM stands for Voltage Regulator Module and is located close to the CPU socket to provide a reliable and clean power supply. The VRM regulates the power from the PSU. In overclocking you modify BIOS settings to instruct the VRM for increased performance at the expense of increased heat output. Motherboards for overclocking come with a high-quality VRM that uses better components. But a VRM always consists of MOSFET's, Chokes, Capacitors, and a PWM Controller. The IC(Integrated Circuit)is there to control and regulate those components.
What is the difference between Ryzen and Zen?
Ryzen and Zen are the same, whereas Zen is the architecture and Ryzen is the product name of the AMD consumer-based CPU's. So Ryzen CPU's are based on the Zen architecture, Zen 1 architecture is used for the Ryzen 1000 series CPU's(Ryzen 1600X et), Zen+ is used for the Ryzen 2000 series CPU's(2600X etc.) and Zen 2 architecture is used for the Ryzen 3000 series(3600X etc.).
Custom settings for your Ryzen CPU's that are provided by AMD, CBS stands for Custom BIOS Settings. Settings like ECC RAM that are not technically supported but work with Ryzen CPU's as well as other SoC domain settings.
Precision Boost Overdrive(PBO) is the AMD automatic overclocking solution for the Ryzen CPÚs. Initially released on the Threadripper HDT CPU's and should not be confused with Precision Boost what dictates the Frequency Range boosting table. It comes default on motherboards that have a design spec of 88w and/or 60A or higher using CPU's that have a 65W TDP or higher.
The internal Vega GPU is the same on all Ryzen APU variants. The RX Vega 11 and RX Vega 8 internal GPU frequency can be overclocked.
|RX Vega||1.100v ~ 1.200v||1.200v ~ 1.400v|
What are save voltages for Ryzen SoC?
SoC voltage is the same for all architectures with the Ryzen CPUs. And are used when overclocking the FCLK(Infinity Fabric) and MCLK(Memory Frequency). And in some cases can help to stabilize CPU overclocking.
|Ryzen SoC||1.000v ~ 1.150v||1.150 ~ 1.250|
Each Zen architecture has it's own AMD recommend, and Community recommended voltages. Save voltages are to ensure your CPU will have a long life span. Dangerous voltages may damage or degrade a CPU. Below is a table for each Zen architecture.
|Zen1 (Ryzen 1000 series)||1.350v ~ 1.375v||1.375v ~ 1.450v|
|Zen+ (Ryzen 2000 series)||1.300v ~ 1.350v||1.350v ~ 1.400v|
|Zen2 (Ryzen 3000 series)||1.275v ~ 1.300v||1.300v ~ 1.325v|
CPU LLC adds extra voltage to compensate for Vdroop when a CPU or GPU is put under heavy load. LLC gives overclocking stability by preventing low or high voltage fluctuations and tries to maintain a stable voltage supply to the CPU or GPU. Higher LLC tends to overshoot more in voltage supply, and a lower LLC tends to undershoot in the voltage supply to the CPU.
It is a threshold for the VRM to shutdown and monitors the current supply to the CPU, setting Current Capability higher will allow for more current supply to the CPU but will increase heat output. This works best if you have an overclock that shuts down the motherboard/PC because the threshold is triggered.
Switching frequency is the transient response of your VRM MOSFETs settings this higher in Mhz will allow for a better transient response at the expense of increased heat output and using a lower setting in Mhz will lower the heat output but lower the transient response. Better transient response in overclocking translates into a more stable voltage supply from your PSU to the CPU.
This will allow for setting the current supply to the internal CPU voltage regulator at the expense of increased heat when set to extreme and lower heat when using optimized or standard. This will help with stability in overclocking and give the best result when using optimized or extreme.
This affects your VRM Power Phases to the CPU, and will be depending on the setting, achieve greater stability in overclocking. Setting Power Phase Control to extreme keeps the number of active CPU power phases at the maximum. If you set Power Phase Control to optimized, there will be a power-saving, but less stability, phases to the CPU will power down.
SOC(AMD) stands for System On Chip and is also known as uncore(Intel) and encompasses all the components, not in the core of the actual CPU but on the same substrate like internal GPU, Cache, I/O Ports, Memory Controller etc. Overclocking SOC settings can help in varying degrees with keeping CPU core components stable.
SOC LLC adds extra voltage to compensate for Vdroop when uncore is put under heavy load LLC gives overclocking stability by preventing low or high voltage fluctuations and tries to maintain a stable voltage supply to the uncore. Higher LLC tends to overshoot more in voltage supply, and a lower LLC tends to undershoot in the voltage supply to the SoC.
It is a threshold for the VRM to shutdown and monitors the current supply to the SoC, setting Current Capability higher will allow for more current supply to the SoC but will increase heat output. This works best if you have an overclock that shuts down the motherboard/PC because the current threshold is triggered.
Switching frequency is the transient response of your VRM MOSFETs settings this higher in Mhz will allow for a better transient response at the expense of increased heat output and using a lower setting in Mhz will lower the heat output but lower the transient response. Better transient response in overclocking translates into a more stable voltage supply to the SoC.
This affects your VRM Power Phases to the uncore, and will be depending on the setting, achieve greater stability in overclocking. Setting Power Phase Control to extreme keeps the number of active SoC power phases at the maximum If you set Power Phase Control to optimized there will be a power-saving, but less stability, phases to the CPU will power down.
What is VDDCR SOC Voltage?
This setting affects the voltage supply to the SoC components. It should be increased when overclocking the CPU core frequency/ratio to aid with better stability of the SoC components as well as the core components. Increasing the VDDCR SOC Voltage will increase the heat output of the CPU package as a whole.
What is CPU Core Ratio?
Sets the clock rate of your CPU by a factor of 10X. So a Core Ratio of 40.00 will multiply the external clock with a base value of 100 to 4,0Ghz.
Sets the voltage for your CPU on a 1:1 ratio, depending on your motherboard you can either enter a manual value of an offset value. So a value of 1.4000 will set the CPU voltage to 1.4 volts using the manual setting.
Stands for Infinity Fabric Clock Speed(FCLK) and can be adjusted with the new Ryzen 3000 series(Zen2). In previous Zen and Zen+ architecture, the Infinity Fabric Clock speed would be set by the DRAM frequency(MCLK). Ideally, you want FCLK to run synchronously(1:1 ratio) with the MCLK for best performance. In short, a DDR4(Double Data Rate) kit is rated for 3600Mhz MCLK and therefor will run synchronously with 1800Mhz FCLK, a 1:1 ratio.
What is the GFX clock frequency?
Sets the clock rate of the internal Vega GPU on Ryzen APUs by a factor of 1:1, so a 1600 value translates into a 1600mhz GPU clock speed.
What is the GFX core voltage?
Sets the voltage for the internal Vega GPU on Ryzen APUs on a 1:1 ratio, so a manual value of 1.25000 is 1.25 volts.
What is DRAM Voltage?
Is the voltage supply to your RAM aka Memory sticks, increasing the DRAM voltage will allow your RAM to run at a higher frequency at times without changing the DRAM Timings but will increase heat output.
This sets the idle states of a CPU when it is not executing commands there a various C-States and serve as a power-saving function. For overclocking, this should be turned off since you want maximum performance at the expense of increased power consumption and helps with keeping a stable overclock.
The main reason to write this FAQ is to supplement guides for AMD Ryzen based CPU's found on this website, and I could not find a one-stop-shop solution for ensuring I nail the explanation for each BIOS settings correctly. You can find my guides for the AMD Ryzen CPU's in the bullet list below.
- Ryzen 5 overclocking the 1600.
- Ryzen 5 overclocking the 1600X.
- Ryzen 3/5 OC'íng the 2200G/2400G APU's.
- Enjoy overclocking, Paul "HisEvilness" Ripmeester