FCLK frequency

In this article, we have explored the idea of FCLK that is Infinity Fabric Clock, FCLK Frequency and how to change it.

Table of contents:

  1. Infinity Clock
  2. FCLK Frequency
  3. How to change FCLK Frequency?

Infinity Fabric

Infinity Fabric is a technology that was launched in April 2017 by AMD. Infinity Fabric is the technology to connect two different components of a system like CPU, RAM and others.

It is a high performance connection that scales data and control flow across connect components. Infinity Fabric has 2 components:

  • Infinity Scalable Data Fabric (SDF)
  • Infinity Scalable Control Fabric (SCF)

SDF is used to transfer data while SCF is used to transfer System Control signals.

FCLK Frequency

FCLK Frequency is the frequency at which Infinity Fabric Clock operates on. Infinity Fabric interconnect core components like CPU, RAM and others and is used for data and control transmission.

FCLK Frequency is the frequency of data and control transmission between different components. Sample value of FCLK Frequency is 2500 MHz. MHz is the unit of frequency and stands for Mega Hertz.

For the series Ryzen 1000 and Ryzen 2000, the FCLK frequency cannot be changed and is hardcoded to the value of RAM frequency. For maximum efficiency of a system, the RAM frequency should be at peak which is around 3000 MHz. In Ryzen 3000 series, the value of FCLK frequency can be changed in BIOS settings.

If the system has a slower RAM, then the value of FCLK Frequency needs to be changed so that efficiency of the system is maintained. Ideally, RAM frequency stays around 3200 MHz while FCLK Frequency stays around 2000 MHz for good performance in general. Higher frequency can degrade the performance but there are exceptions.

By suggestion, the ratio of RAM frequency to FCLK frequency should be 1:1.

How to change FCLK Frequency?

FCLK Frequency can be set manually to a specific value using BIOS settings. The steps to set FCLK Frequency is as follows:

  • Enter BIOS: While your system starts, press "delete" key to enter BIOS settings. The key varies across systems.
  • Once you enter BIOS, go to the following options to set Clock Frequency to Manual mode.
Advanced -> CBS -> NBIO Debug Options -> XFR Enhancement -> Manual

By default, it is set to "Automatic" so the options to set frequency values are not available. Once you have set the above option to "Manual", you can set different CPU frequency values.

The next step is to set the FCLK Frequency. Follow the following steps:

Advanced -> CBS -> NBIO Debug Options -> XFR Enhancement -> FCLK Frequency

Enter the desired frequency value manually. Note that the values are in hexadecimal.

FCLK Frequency is equal to RAM frequency.

With this article at OpenGenus, you must have the complete idea of FCLK: Infinity Fabric Clock.