Por que a velocidade do clock configurada foi alterada depois que adicionamos duas placas dimm

temos máquina Linux com DELL HW, e máquina tem 256G de memória

antes de adicionar o novo cartão DIMM com 32G, verificamos que Configured Clock Speedé 2400MHz

então depois adicionamos 32G adicionais ( 2 cartões DIMM , o mesmo tipo de cartão DIMM que a máquina já possui ) a esta máquina e após a inicialização da máquina , verificamos o Configured Clock Speedby dmidecodee vemos que ele foi alterado

então Configured Clock Speedfoi alterado de 2400MHzpara1866 MHz

exemplo

antes de adicionar o novo DIMM

dmidecode | grep "Configured Clock Speed"
        Configured Clock Speed: 2133 MHz
        Configured Clock Speed: 2133 MHz
        Configured Clock Speed: 2133 MHz
        Configured Clock Speed: 2133 MHz
        Configured Clock Speed: Unknown
        Configured Clock Speed: Unknown
        Configured Clock Speed: Unknown
        Configured Clock Speed: Unknown
        Configured Clock Speed: Unknown
        Configured Clock Speed: Unknown
        Configured Clock Speed: Unknown
        Configured Clock Speed: Unknown
        Configured Clock Speed: 2133 MHz
        Configured Clock Speed: 2133 MHz
        Configured Clock Speed: 2133 MHz
        Configured Clock Speed: 2133 MHz
        Configured Clock Speed: Unknown
        Configured Clock Speed: Unknown
        Configured Clock Speed: Unknown
        Configured Clock Speed: Unknown
        Configured Clock Speed: Unknown
        Configured Clock Speed: Unknown
        Configured Clock Speed: Unknown
        Configured Clock Speed: Unknown

depois de adicionar o novo DIMM

  Configured Clock Speed: 1866 MHz
        Configured Clock Speed: 1866 MHz
        Configured Clock Speed: 1866 MHz
        Configured Clock Speed: 1866 MHz
        Configured Clock Speed: 1866 MHz
        Configured Clock Speed: 1866 MHz
        Configured Clock Speed: 1866 MHz
        Configured Clock Speed: 1866 MHz
        Configured Clock Speed: 1866 MHz
        Configured Clock Speed: Unknown
        Configured Clock Speed: Unknown
        Configured Clock Speed: Unknown
        Configured Clock Speed: 1866 MHz
        Configured Clock Speed: 1866 MHz
        Configured Clock Speed: 1866 MHz
        Configured Clock Speed: 1866 MHz
        Configured Clock Speed: 1866 MHz
        Configured Clock Speed: 1866 MHz
        Configured Clock Speed: 1866 MHz
        Configured Clock Speed: 1866 MHz
        Configured Clock Speed: 1866 MHz
        Configured Clock Speed: Unknown
        Configured Clock Speed: Unknown
        Configured Clock Speed: Unknown

então qual poderia ser a razão para isso mudou? , por que adicionando uma memória dimm , depois Configured Clock Speedmudou assim?

Server is Dell PowerEdge R730 and memories are:

Memory Device
    Array Handle: 0x1000
    Error Information Handle: Not Provided
    Total Width: 72 bits
    Data Width: 64 bits
    Size: 16384 MB
    Form Factor: DIMM
    Set: 3
    Locator: A9
    Bank Locator: Not Specified
    Type: DDR4
    Type Detail: Synchronous Registered (Buffered)
    Speed: 2400 MHz
    Manufacturer: 002C0632002C
    Serial Number: 1B42681B
    Asset Tag: 001808A0
    Part Number: 18ASF2G72PDZ-2G3D1
    Rank: 2
    Configured Clock Speed: 1866 MHz
    Minimum Voltage:  1.2 V
    Maximum Voltage:  1.2 V
    Configured Voltage:  1.2 V