Memory: Gear Mode on AMD platforms

Currently, on AMD’s X870E and X670/E and other chipsets, for EXPO profiles to boot 6400MHz and above you may need the memory controller to run at half speed of the system memory system (1:2).
Some motherboard manufacturers enable this “tweak” by default, but some others don’t.

If your Corsair EXPO memory kit doesn’t boot at speeds 6400MHz and above, then try the following steps that may help to resolve the issue.

Enter your system’s BIOS and find the following options:
 

• ASRock
  In the OC Tweaker tab, find the UCLK DIV1 MODE and change the option to UCLK=MEMCLK/2.
  
• ASUS
  In the Extreme Tweaker tab, find the DRAM Timing Control menu and press Enter. Find UCLK DIV1 MODE and change to UCLK=MEMCLK/2.

  

• GIGABYTE
  In the Tweaker tab, find the UCLK DIV1 MODE option and change it to UCLK=MEMCLK/2.

  

• MSI
  In the Overclocking tab, find UCLK DIV1 MODE and change it to UCLK=MEMCLK/2.