Slow FW800 Hard Drive

Discussion in 'Mac Accessories' started by gretsch27, Jan 8, 2010.

  1. gretsch27 macrumors newbie

    Joined:
    Feb 3, 2009
    #1
    I bought a MacAlly GS350SUAB hard drive enclosure for the firewire 800 port. Before I made the purchase, I looked around for some FW800 drive xbench scores and found a few results:

    http://www.mcelhearn.com/2009/07/19...l-hard-disk-speed-comparisons-and-benchmarks/

    http://www.mymac.com/showarticle.php?id=652

    http://discussions.apple.com/thread.jspa?messageID=10652532

    http://www.chipchick.com/2008/09/seagate_freeagent_desk_drive_mac.html?pid=839

    When I ran the xBench disk test on my drive, I was unimpressed. They weren't much better than when I plugged it in using the USB port.

    Uncached Write 34.81 MB/sec [4K blocks]
    Uncached Write 43.62 MB/sec [256K blocks]
    Uncached Read 18.11 MB/sec [4K blocks]
    Uncached Read 46.06 MB/sec [256K blocks]

    I thought maybe xBench was sucking, so I timed how long it took to write a 831MB file to the drive using both USB and FW800, and it was actually faster (marginally) on USB. FW800 took 30 seconds, while USB took 28. Something doesn't seem right.

    Does anyone have any thoughts on why this could be? I do have a FW400 audio interface hooked up, but that is of course plugged in to the FW400 port and shouldn't make a difference. The hard drive I'm using came out of a Seagate FreeAgent. Is it possible it's just a really slow drive?
     
  2. MisterMe macrumors G4

    MisterMe

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    Jul 17, 2002
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    USA
  3. gretsch27 thread starter macrumors newbie

    Joined:
    Feb 3, 2009
    #3
    Is there a point you're trying to make? That link to a google search for the wrong enclosure doesn't indicate why my enclosure is not getting fw800 speeds.
     
  4. Artful Dodger macrumors 68020

    Artful Dodger

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    #4
    Are you using the iMac or MB with the drive? I won't assume either as both are in your sig but not listed for your results. What was the speed of the drive when it was in the other enclosure if it was from another enclosure? Also do you have the FW800 plugged into the FW800 port on the iMac first and not chained through the audio interface? Just trying to make sure it's clear to help you better :)

    Further looking revels that the Free Agent drives are mostly 5400rpm drives and not 7200. That would make a difference even if it is slight in short bursts. So at this point without much knowledge about the HDD itself, I'd say the enclosure is not the issue at hand but the drive itself. The links are really moot because they don't take into account the HDD that you have paired with the enclosure as they are really guide lines at best but you get the idea I hope.
     
  5. MisterMe macrumors G4

    MisterMe

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    Location:
    USA
    #5
    My bad. I didn't notice the "B." This is the link to information your specific enclosure. I disagree with Artful Dodger that the enclosure doesn't matter. However, I think that we agree on the larger point. You researched neither your specific drive nor your specific enclosure.

    Without access to the schematic of the enclosure, I suspect that your enclosure communicates primarily through its USB port. I also suspect that its FireWire port is routed through a FireWire-to-USB adapter. This would account for the USB port's being faster than your FireWire port.
     
  6. gretsch27 thread starter macrumors newbie

    Joined:
    Feb 3, 2009
    #6
    This is all on my iMac. The audio interface is entirely separate. That's plugged in to the FW400 port, and the drive is plugged in to the FW800 port.

    I swapped the drive (7200 rpm Seagate Barracuda) with a 7200 rpm WD Caviar and got much better results... Almost as good as my internal drive.

    Uncached Write 73.51 MB/sec [4K blocks]
    Uncached Write 63.87 MB/sec [256K blocks]
    Uncached Read 17.06 MB/sec [4K blocks]
    Uncached Read 73.67 MB/sec [256K blocks]

    This is probably why people like using FW800 drives as their system drive on the mac mini.

    As a sanity check I tried it on usb and couldn't get the same speeds, so I'm pretty certain it's the hard drive. As I said, the Seagate came out of a FreeAgent external enclosure. When I took it apart to get the drive, it was clear that it was never intended to be a user serviceable. They must just put some POS drive in there because it's not supposed to exceed USB 2.0 speeds anyway.
     
  7. Cliff3 macrumors 65816

    Cliff3

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    Nov 2, 2007
    Location:
    SF Bay Area
    #7
    Try unplugging the FW400 device and run your tests again. I briefly kept the FW400 hub in my ACD connected to my Mac Pro (via an adapter, of course) until I determined that it slowed down the entire firewire subsystem, and that's without any FW400 devices being connected to the hub.
     
  8. MisterMe macrumors G4

    MisterMe

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    #8
    You misunderstood my post. Everything is not in your Mac. The enclosure has its own electronics. The enclosure communicates with the outside world via USB 2.0, FW400, or FW800 depending on your connection. The drive that you install in the enclosure obviously uses none of these protocols. The internal electronics of the enclosure must translate data both ways between the installed drive and each port. For each port to have its maximum throughput, each port needs independent access to the drive. It may the access but I doubt it. My bet is that the enclosure routes all data though its USB electronics and that its FireWire ports communicate through internal adapters to the enclosure's USB electronics. As I said in my earlier post, this would explain why your USB port is fastest.
     
  9. Artful Dodger macrumors 68020

    Artful Dodger

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    #9
    That is what I meant, the links and the missing info doesn't help. Not sure why I typed enclosure other than a moment of loosing my mind earlier today ;) Thanks for taking it easy on me :D Also I wasn't sure how old the drive was meaning what did it come out of which he answered and what speed if all other things were equal, which they weren't.
     

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