Can enternal HD only daisy chain with FW?

Discussion in 'Buying Tips and Advice' started by Bertmg, Oct 22, 2009.

  1. Bertmg macrumors member

    Joined:
    Feb 8, 2008
    Location:
    San Diego, CA
    #1
    I heard that for external HD to be able to daisy chain and maybe convert into different RAIDs, the Hard drives must be connected to each other and to the laptop all with the same type of connections format.

    So

    LAPTOP HD1 HD2
    FW 400/800 + FW 400/800 + FW 400/800 = Yes
    USB + FW 400/800 + FW 400/800 = No
    ESATA + FW 400/800 + FW 400/800 = No
    ESATA + USB2 + USB2 = No

    Is this true?
     
  2. spinnerlys Guest

    spinnerlys

    Joined:
    Sep 7, 2008
    Location:
    forlod bygningen
    #2
    As Firewire, S-ATA and USB are different buses, you can't daisy chain hard drives mixed via those buses.

    And only Firewire is able to daisy chain external devices, the other two don't have that option.

    With Firewire you'll be able to chain up to 63 devices together, but the device with the lowest speed (FW 400 or FW 800) will determine the speed of all the other devices.
    In other words, one FW 400 device in a chain with 62 other FW 800 devices will make the chain only work at the maximum speed FW 400 provides.


    So in short: It is true.
     
  3. gr8tfly macrumors 603

    gr8tfly

    Joined:
    Oct 29, 2006
    Location:
    ~119W 34N
    #3
    Just a note on mixed 800/400:

    With mixed FW800 & FW400, and FW800 had the head of the chain, I get full FW800 speeds (or, at least the unsaturated HD transfer rate which is much higher than FW400). I have 3 FW800 HDs, followed by 3 FW400 devices (2 HD, one burner).
     
  4. spinnerlys Guest

    spinnerlys

    Joined:
    Sep 7, 2008
    Location:
    forlod bygningen
    #4
    It's good to know to put the FW 800 ahead of the others. I will try it sometime.
    Thanks for the hint.
     

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