cMP 1,1 HDD negotiating speed 1,5 gigabit?

Discussion in 'Mac Pro' started by drasl, Jan 14, 2016.

  1. drasl macrumors member

    Jul 3, 2014
    I just picked up a 2,66 ghx 1,1 Mac Pro for next to nothing and installed lion on a HDD for the OS.

    Although I am just using a 3,5” HDD it does seem a bit slow and when I go to the system profiler it states that the link speed it 3 gigabit but the negotiated speed is 1.5 gigabit.

    The same HDD showes up with a 3 gigabit negotiated speed on my Mac pro 3,1.

    I have heard a lot about negotiated speeds with certain macs and SSDs but never with HDDs.

    Is this normal and if not any ideas ?
  2. Surrat macrumors 6502


    Jun 20, 2014
    United States
    My macpro 1,1 is using 2015 production seagate drives, and they show up as 3gbit.

    I suppose you might have found the one very rare drive thats not really compatible?
    It could also just be dust in your sata connecter on the motherboard, blow it out real good to ensure its clean.
  3. drasl thread starter macrumors member

    Jul 3, 2014
    The strange part is that I have tried a couple of more 3,5" drives and they all show a negotiated speed of 1,5 but a SSD in a 2,5" to 3,5" adaptor shows negotiated speed of 3
  4. 666sheep macrumors 68040


    Dec 7, 2009
    Start with PRAM (and SMC) reset. Won't hurt, could help.
  5. drasl thread starter macrumors member

    Jul 3, 2014
    Tried them all but all my mechanical drives appear as 1,5.

    Im starting to think there is something going on with the logic board since I tried updating to ElCapitan (with the Efi boot) and the computer starts and runs for 90 seconds before shutting down, every time.

    Now Im running Yosemite without issues but still showing 1,5 in negotiated speed on mechanical drives and 3.0 on SSDs.

    I guess this one will probably not be solved.
  6. haralds macrumors 6502a


    Jan 3, 2014
    Silicon Valley, CA
    1.5GB is likely still in excess of the actual reading and writing speed of the old drive.

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