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

    Apr 28, 2009
    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


    Jan 9, 2004
    Grand Rapids, MI, USA
    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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