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What is FCLK frequency?

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There are a lot of different parameters that decide a processor’s performance, including different clock types and speeds. This can make for some confusing decisions when looking for a new CPU. Not to mention, Intel and AMD have their own parameters, which further makes a choice difficult. 

In this article, we’re looking at what FCLK is, including the FCLK frequency and telling you everything you need to know.

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What is FCLK?

Modern processors are made up of different components, including caches—memory controllers and the CPU itself. In AMD processors, all these systems are connected by Infinity Fabric which is responsible for data transmission and control of all the connected components. 

The Infinity Fabric architecture was introduced in AMD’s Zen 2 architecture which removed the FCLK from the memory giving the BIOS independent control. FLCK is the clock speed that controls the Infinity Fabric’s operational performance. 

FCLK makes overclocking RAMs relatively easy and provides control over parameters like timings and voltages, helping the RAM operate at an even higher speed. 

FCLK clocks aren’t the only ones present in Ryzen CPUs either. They also include the following clocks.

  • UCLK: The operational frequency of the Unified Memory Controller.
  • MCLK: Internal and external memory clock.
  • LCLK: The line clock where the I/O Hub controller talks to the chip.
  • CCLK: CPU’s core clock speed.

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Should you increase your FCLK frequency?

For optimal performance, your FCLK frequency should be half of your RAM clock speed. If you’re running 3600MHz RAM, your FCLK should be set at 1800MHz. Additionally, the FCLK, UCLK and MEMCLK are all synchronised together, so you should always maintain a 1:1 ratio. 

You can increase your FCLK frequency to get more performance out of your RAMs, but that’ll also run the risk of destabilising them. You can end up desynchronising the RAM latency and cause problems like Blue Screen of Deaths and other critical system crashes. 

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Yadullah Abidi

Yadullah Abidi

Yadullah is a Computer Science graduate who writes/edits/shoots/codes all things cybersecurity, gaming, and tech hardware. When he's not, he streams himself racing virtual cars. He's been writing and reporting on tech and cybersecurity with websites like Candid.Technology and MakeUseOf since 2018. You can contact him here: