HDD daisy chaining speed ?

Discussion in 'Buying Tips and Advice' started by Temujin, Dec 1, 2006.

  1. Temujin macrumors 6502a


    Oct 1, 2005
    I just received my second Lacie Tripple Interface harddrive :D
    I now have two and I've daisy chained the two using a FW800 cable.
    My MBP connects to the drives using a FW400 cable (not a C2D owner :()

    I was starting a transfer of 100GB of data from the old drive to the new and started wondering if transferring data using the daisy chain is faster or slower than connecting one USB2 and one FW400 to the MBP.

    What would you recommend?
  2. tdhurst macrumors 68040


    Dec 27, 2003
    Portland, OR

    Both FW 400 and 800's sustained speed is faster than USB2's, so I'd say the daisy chained option.

    Could be an interesting thing to find out though. Any chance you want to time a file transfer via both options?
  3. Edge100 macrumors 68000

    May 14, 2002
    Where am I???
    Test it.

    In practice, you get about 30-35MBps over FW400, and about 20MBps over USB2.0.

    Since you're just copying files from one drive to another, you should be getting the full FW bandwidth, and in that case USB2 would be much slower.

    The issue comes when you start overloading the FW bus with data. Two FW drives, both requiring data at the same time (with total data requirements greater than 30-35MBps), will each use about 15-17MBps of the 30-35MBps actual throughput (assuming they split the bandwidth equally). A USB2 drive should be right around there on its own, so for daily use, it would be a toss up.

    I say test it both ways
  4. Temujin thread starter macrumors 6502a


    Oct 1, 2005
    As you guys suggested I did a test.

    Data size: 6.91GB

    Daisy FW800 = 6 min 5 sec
    USB2/FW400 = 5 min 43 sec

    So the daisy chain loses. I would have thought that the FW800 daisy chain connection would outperform the USB2/FW400 approach. Hmm

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