firewire adapter bus power: the retina is definitely a regression

Discussion in 'MacBook Pro' started by grrrz, Aug 2, 2012.

  1. grrrz, Aug 2, 2012
    Last edited: Aug 13, 2012

    grrrz macrumors member

    Jan 31, 2012
    edit: since I find this thread linked from music forum as a "source of knowledge", and as I don't have the actual knowledge, here is all I know:
    -the theorical 45W of power is only theorical (you can imagine why since mbp power supplies are 65/85W)
    -my MOTU ultralite mk3 (not hybdrid) also theorically draws 12W of power, it says so in the manual, the ultralite mk3 hybrid does too. if you don't know, there should be your answer for your particular hardware.
    we now know from this guy
    that it doesn't work with the adapter as we could suspect just reading the data.
    -as for the actual power you can drive from the native firewire port on the classic line of mbp, I can't find any reliable answer to that (and it drives me mad, as I've searched all over the internet). I haven't got the point to test it out myself with a voltmeter since I don't want to risk frying it, and apple "knowledge base" only says "minimum 7W", which doesn't says much.
    I've red a few times that 7W was already the standard on mbp computer, but from the info above it seems not, my motu works fine on a late 2011 13" mbp, so it's at least 12W. Also red 18W somewhere. something between 12 and 18W seems realistic.

    original post:
    Maybe we already knew it, but with the release of the fw800 adapter comes officialy a definite long term regression for audio pro and enthusiast. Yes now we can plug a firewire peripheral to the new generation (soon to be only generation) retina macbook, but that comes at a price: the bus power of thunderbolt is a lousy 10W (for a max voltage I can't find, probably something modulable between 9 and 20), and the adapter taxes 3W so get a 7W bus power adapter for the apple adapter, that's really not enough to power most audio hardware (my ultralite mk3 requires 12W)
    and so on-location "pseudo-portable" recording away from power source becomes impossible with only firewire hardware and a computer.
    I don't understand why a so called next gen interface has a so low bus power, against the fw 800 for exemple (up to 45W, up to 30V).
    Is there really a good reason?
    even 20-30W would be plenty. So here's an usage that's probably lost for now (unless the specifications of thunderbolt evolve)
    Usb 2 interfaces are no match latency and cpu usage wise to firewire, so the workaround is either hybrid (usb2 for portable application, firewire for others), or using a home made battery, or an interface that support pro standard batteries, the motu traveler does;
    And even if they release full thunderbolt sound interface the power problem will be the same.
    shame for a standard apple carried itself and dropped in an instant.
    Other problem is even on the pc side bus powered fw400 (let alone fw800) is really hard to find. It was even a good reason to buy a mac over a pc few years back (a lot of musicians I know did, and bought the good old white macbook which was cheap and perfect for this).
    just a thought
  2. grrrz thread starter macrumors member

    Jan 31, 2012
    well I was going to revise my judgment reading here and there that the native firewire port from the classic mbp generation also delivered up to 7W but according to the tests from this guy:
    his MOTU ultralite doesn't power up from the fw bus from the adapter.
    (by the way "spiral" references this post, which was less informed than his since I didn't actually tested it, so thanks to him for the heads up).
  3. AZREOSpecialist macrumors 68020


    Mar 15, 2009
    Why is any of this a surprise? Doesn't anyone read anymore before buying?

    Under the "One small port. One giant leap in possibilities" section it clearly says that Thunderbolt delivers 10 watts of power. How could you miss this?
  4. grrrz thread starter macrumors member

    Jan 31, 2012
    yes, no need to be patronising we can read, we can also read that the adapter delivers 7W (like said on the product description), and we could anticipate that, no we're sure, and that doesn't change the fact that people can no longer expect their hardware to work as they used to with this adapter, and that sucks, because bus power was really helpful in a lot of situation.
    That also doesn't change that there's no information on the power the native fw on those classic MBP delivers, which could give an indication on what to expect from the adapter when there's no way to know what power they need. because it's supposed to be a niche thing apple doesn't give a sh.t to get the actual specific data for each model available.
  5. Matt Leaf macrumors regular

    Feb 5, 2012
    I feel terribly sorry for external hardware companies everytime apple changes i/o. Especially MOTU, who backed firewire the whole way... worrying about what to do with my Ultralite MK1 now too...
  6. terraphantm macrumors 68040

    Jun 27, 2009
    I don't know about MBPs, but I know the iMac's FireWire port is also limited to 7W according to apple. Considering the iMac is powered by the mains and the MBP isnt... I wouldn't be surprised of the MBP has a similar limit officially.

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