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I'm trying to back up some data on an external hard drive and am finding the transfer rate to be unbearably slow.

My environment is as follows:

  • Macbook Pro Unibody (late 2008)
  • Windows 7 RC, 64-bit
  • Lacie, rugged 500GB portable hard drive

I have tried using a number of methods including simple copying in Explorer, Teracopy, Crashplan, and Windows backup. I am averaging around 1MB/s which seems terribly slow.

How do I identify what is the cause of this slow file transfer, and then how do I go about addressing the issue.

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1MB/sec is crazily slow - there's definitely a problem.

The cause, or causes, could be :

  1. Are you copying many small files?
  2. Are there any background processes running?
  3. Is the driver correct?
  4. Something wrong with the Lacie drive?

Speaking about driver... I found an interesting quote here vis-a-vis slow Firewire (1394) transfers too.

Just go to Device Manager and do Update Driver on 13494 OHCI, then from the list of available drivers choose the following one 1394 OHCI Compliant Host Controller (Legacy) .

You might want to give it a shot.

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1. Its a mix of large and small files 2. Nothing in the background 3. Will just try your driver advice and get back to you 4. The Lacie is fine because I tried USB right after posting the question here and I was getting rates between 4-18 Mbps and averaging around 7Mbps. So its definitely the Firewire – dtmunir Sep 5 '09 at 4:29

IEEE 1394 (aka FireWire) and USB stem from a time that most computers had significantly less than 4GB of memory. As a result the designs from these old times is sometimes limited to 4GB internal address space.

What does this mean for you?

  • if you have less then 4GB memory things just work.
  • If you have more then 4GB memory then things either do not work at all, or an extra in memory copy is needed, slowing things down.

Think of it as someone who has learned to write to single digit pages (pages 0 to 9). If you ask them to read from page 11 then someone else first has to copy page 11 to a page in the range 0-9, and then the person can read it. This double buffering slows things down.

How does this apply to you?

You wrote you have the 64 bits version of win7. That one allows you to use more then 4GB memory. However you did not actually post that. thus:

1) Please add to the OP how much RAM you have.
2) Try booting the system with 4GB or less and see if the problem persist.

If the problem goes away, install thos patch (as already mentioned by Lloyd).

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