Mac Mini + 1TB MyBook + 2TB MyBook Studio Edition II - slow transfer?

Discussion in 'Mac Basics and Help' started by CharlesCA, May 6, 2009.

  1. CharlesCA macrumors newbie

    Joined:
    Apr 28, 2009
    #1
    How long should it take to transfer 430gb from a 1TB WD MyBook to 2TB MyBook Studio II Raid 1 over firewire 400 on my Mac Mini Core Solo 1.5Ghz, 2gb ram.

    It goes Mac Mini - (firewire 400) -> 1TB WD MyBook -(firewire 400 to 800 cable) -> 2TB MyBook Studio II Raid 1 (mirror).

    I performed the firmware update on the Studio II.

    It's estimating 7 hours for 430gb - all movie files around 700mb each. Does that sound right?
     
  2. mkrishnan Moderator emeritus

    mkrishnan

    Joined:
    Jan 9, 2004
    Location:
    Grand Rapids, MI, USA
    #2
    Seems, if anything, only very slightly on the long side... this is the way I understand the calculation:

    Firewire 400 = 400 mbps = 50 megabytes per second.
    430 gb = 430,000 mb

    Now I think the rub is that the data has to pass through the firewire bus twice -- as I understand it, there's no direct data copy that avoids having the data go to the computer.

    So the theoretical maximum speed of transfer is actually 25 megabytes/s.

    At that rate, 430 gb / 25 mb/s = 17,200 s = 286 minutes = just under five hours.

    Given your drives' abilities to maintain that kind of transfer rate (especially the writing drive), then, unless I'm doing the calculation wrongly, the 7 hours is probably not unreasonable....
     

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