Firewire 400 camera shuts down 800 bus

Discussion in 'iMac' started by kirsch92, Jun 2, 2009.

  1. kirsch92 macrumors member

    Apr 30, 2009
    I bought a 2 bay FW 800 drive box which uses the Oxford 924dsb chipset which is a highly regarded chipset from what I have read. I use one drive for Time Machine, the other was to be for video capture.

    I have captured from my FW 400 DV camcorder successfully to the internal drive prior to this problem.

    The problem:

    If I connect the camcorder to the FW 400 port (on either the drive box or the iMac) it disconnects my FW 800 drives AND the camcorder won't show as available.

    Is there a problem using the these firewire buses at the same time?

    The drive box has it's own power supply as well. It's a Sans Digital MS2C1 running in JBOD mode. The iMac is a late 2008 24" 2.8 gHz with 4 gig RAM.

    I can capture to the internal and then transfer iMovie 09 events to the external later, but that isn't really what I wanted to do.
  2. spinnerlys Guest


    Sep 7, 2008
    forlod bygningen
    It shouldn't disconnect the other drives.

    But if you daisy chain a FW400 device to FW800 devices, the speed of the complete system will slow down to FW400 speeds, even if the FW400 device is the last in the chain.

    As from what I understand from your post, you connect the FW400 camera to the FW400 port on the iMac and the FW800 drive(s) to the FW800 port on the iMac?
    Is that correct?

    And if it is, and you connect like this all FW (400 & 800) devices unmount.

    Have you looked at Disk Utility, if at least the drives are recognized, but not mounted?

    Also, you could try an SMC reset for your iMac.

    Shut down the computer, unplug everything, USB, FW, etherner, external display, audio and power plug - everything.

    Wait for 15 seconds (I wait a bathroom visit), then plug the power, keyboard and mouse back in, start the computer and wait till it completed the boot and log in process.
    After that attach your FW800 drive and the camera, and see if that helped.

    Also, plug the camera in before iMovie starts and switch it to Play.
  3. eric44 macrumors member

    May 18, 2008
    Don't know if this helps but I had a similar problem last year with my (two months old) iMac.
    Whenever I connected my DV camcorder to the FW400 port it wasn't recognised. Also the iMac kicked my external drive off the FW800 port and the firewire bus crashed.
    After much communication with Apple and two visits to the genius bar they changed the machine for a new one.
  4. kirsch92 thread starter macrumors member

    Apr 30, 2009
    That is correct.

    I played around a bit more, tried an SMC reset. I also hooked up the drives using USB and the camera worked in iMovie, so it's a firewire issue, not an iMovie issue.

    Under Disk Utility the drives completely disappear. As soon as I unplug the FW400 from the camera, they reappear and remount.

    I did find one other post on Apple support groups that made mention of a similar problem, there was no resolution other than they thought it might be a camera issue. Two year old post.
    I can live with this, my only concern is the thought that the bus in the iMac might be faulty.

    I think I might have to find someone to borrow another camera and a drive from to test.
  5. kirsch92 thread starter macrumors member

    Apr 30, 2009
    I am curious how similar our problems are. Did your 400 bus work if your external 800 was turned off or disconnected?

    What did they do at the Genius Bar? I am thinking of doing that just to see if they will test with other firewire hardware, if that's something they will do.

  6. kirsch92 thread starter macrumors member

    Apr 30, 2009

    Just had to use the right words when searching.

    My camera is a Canon ZR-60. They symptoms sure fit.

    Thanks for the input though.'

  7. gr8tfly macrumors 603


    Oct 29, 2006
    ~119W 34N
    A bit off topic, but had to chime in on the FW800/FW400 mix.

    I've seen that quoted several places, but the data doesn't show it (both with my own tests and tests I've seen).

    I've done tests on two different machines (2.33MBP and 2.66 UB MBP 17"), and there's a definite speed improvement on transfers to/from internal to FW800 drive, with FW400 downstream. (Also, the speed is the same with or w/o the FW400 downstream).

    Tests on a ~800MB DMG file (the 10.5.7 combo updater) to/from internal 320GB 7200RPM (WD Scorpio Black) (just using Activity Monitor for measurement):

    Seagate FreeAgent Desk Mac FW800 1TB(first in chain)
    read: 68MB/s
    write: 68MB/s

    Seagate FreeAgent Pro FW400 750GB(about 3rd in chain, after two other FW800s)
    read: 36MB/s
    write: 36MB/s

    This jives with data I've seen in other reports using XBench.

    Right now, I have 5 drives, plus a DVD burner on the single FW800 port on the 17" UB MBP. Three FW800, two FW400, then the FW400 burner. I think the 68MB/s is pretty much the limit for the WD 320GB 7200RPM anyway (real-world, that is...).

    I just wanted to throw this data out there for others interested (and forced) into mixing FW800 & FW400 on the same bus.
  8. cube macrumors P6

    May 10, 2004
    I experience a similar thing with my Cube's FireWire 400.

    If I turn on my Formac Studio DV/TV, it stops and corrupts the backup made through my FireWire/SCSI converter.
  9. eric44 macrumors member

    May 18, 2008
    When I took my iMac in the Genius managed to get the iMac to recognise my camcorder on FW400 if he booted it off an external drive. He told me to do a reinstall which did not work. Applecare eventually helped by looking at the error codes generated. It appeared that there was something wrong with the firewire bus because when you connected the camcorder it crashed the bus and stopped the FW800 port working as well.
    It was because of their intervention that the iMac was changed - the error codes indicated something serious was wrong internally and they had no choice but to change the machine.
  10. kirsch92 thread starter macrumors member

    Apr 30, 2009
    Thanks for the info. I'm going to borrow a different brand of camera and see if it works; I suspect it will.

    If not I will go the Genius route, just be safe. :)

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