• Close Photoshop
  • Navigate to HKEY_CURRENT_USER\Software\Adobe\Photoshop\120.0
  • Right click on 120.0 and create a new DWORD.

image001

  • Rename the DWORD value to "OverridePhysicalMemoryMB".
  • Right click on it and select modify.
  • Change the base value from "hexadecimal" to "decimal".
  • Change the value data from "0" to "24000".

image002



(https://forums.adobe.com/thread/2416657)