4TB in 27" Mid 2010 iMac - not readable...

Discussion in 'iMac' started by davidtkp, Nov 4, 2013.

  1. davidtkp macrumors newbie

    Nov 4, 2013
    Hi All,
    I've spent the past hour trawling through the net and macrumors looking for a solution to a problem I have.

    I originally had a 1TB seagate on my Mid 2010 iMac. With applecare expiring last month, I very boldly decided to perform some surgery and add a 500gb SSD, while upgrading the HDD to a 4TB WD Caviar Black.

    I've managed to successfully install Snow Leopard from the iMac discs onto the SSD, upgraded to Mavericks. However, all this time, I have been unable to format my 4TB hdd. The symptoms are:
    - Listed in Disk Utility, but does not have a drive name
    - All options/buttons for First Aid/Erase/Partition/RAID/Restore are greyed out and cannot be clicked.
    - Disk details as below:
    Disk Description : WDC WD4001FAEX-00MJRA0 Media
    Total Capacity : 0 Bytes
    Connection Bus : SATA
    Write Status : Read/Write
    Connection Type : Internal
    S.M.A.R.T. Status : Not Supported
    Partition Map Scheme : Unformatted

    Everytime I start up the iMac, I get a pop up alert "The disk you inserted was not readable by this computer." with an option to Initialize (brings up Disk Utility as above), Ignore, or Eject.

    I am wondering whether there is something I've missed, or if my HDD is dead, or if there is a compatibility issue between the HDD and the iMac.

    Help me macrumors forum, you're my only hope!
  2. davidtkp thread starter macrumors newbie

    Nov 4, 2013
    I've just had a chat with a friend, and he told me that the brands should match the original drive I have on my machine. Seeing I have a Seagate and replaced it with a WD, could this be the issue? Anyone?
  3. elithrar macrumors 6502


    May 31, 2007
    That's not the issue.

    - Have you tried using the drive in an external caddy to test that it functions? (might be the cheapest option)
    - Can you format the drive (GPT) from another machine you have at hand/can borrow from a friend/can get to?
  4. davidtkp thread starter macrumors newbie

    Nov 4, 2013
    I have a barebones setup (cables only) I will be borrowing from a friend tomorrow to do some testing with.

    If the test above is successful, I might try formatting it there and reinserting it into the machine.

    I also have another Seagate 4TB (5900rpm NAS drive) which I will try to swap over tonight. If it does work it would indicate that the 'same for same' drive replacement holds some weight. However until I get more testing done it is all speculative.

    It would be good if I could hear from other 2010 imac owners who have replaced their HDD's, whether they stayed on the same brand, and what sizes they have changed to. I've not read any testimonial about anyone going to 4TB.
  5. wangtele macrumors newbie

    Nov 25, 2013
    Does your 4TB hard drive installation was successful in 2010 iMac on it?
  6. scottsjack macrumors 68000

    Aug 25, 2010
    I installed a 2TB Caviar Black drive in a 2010 iMac 21.5" (along with a Blu-ray reader from OWC and some left-over RAM. The WD drive instantly made the iMac seem a little more responsive than it previously was before the cheapest-piece-of-trash-you've-ever-seen OEM Seagate 1TB drive failed.

    I did have to buy software to control the fan speed since the WD did not have the temp sensor connection on it. That was not a big deal because the drive I used was an extra that was just sitting around doing nothing.

    Somewhere on the Net I saw instructions for replacing the plug-in HD temp wiring with a stick-on one like the OD has. This repair was for a family member and it needed to ship so I just went with the software fan mod.
  7. Jambalaya macrumors 6502a

    Jun 21, 2013
    Firstly I don't believe it's a "same manufacturer" issue

    I suspect the problem is that the disk may well not be physically connected properly. Either put the original disk back whilst keeping the SSD and/or try an external casing / cabling (which I see you are doing).
  8. Dopeyman macrumors 6502a

    Sep 5, 2005
    Los Angeles!
    I Think this might be an iMac issue.... It can't handle a drive larger than 2TB...

    I had a similar problem with a 3TB hard drive...

    Same issues as the OP...

    So I gave up and just put in a 2TB WD drive and all is fine.... I use a 64GB SSD drive as my boot drive and use the 2TB as my "storage" drive...

    I put the 3TB drive in my time capsule.... It seems to be doing ok in there...
  9. lekiu, Feb 5, 2014
    Last edited: Feb 5, 2014

    lekiu macrumors newbie

    Feb 5, 2014
    wd4001faex iMac 2009

    you need to disconnect the temp sensor cable!
    use a LCD or optical drive sensor instead, and your drive will work.

    non apple hard drives does use this ports/connectors not as vendors use it on "public/non OEM" devices

    something like this

    thermal sensor from iMac 21/27 2009/2010/2011 will work, doesn´t matter if optical drive, Display or ambient
  10. FatLip macrumors member


    Jun 12, 2013
    on da moon
    old post but same machine and same problem here, you need to format in osx 10.8 or the latest mavericks 10.9 (now) , i have two Seagate 4TB drives, formatted the same exact way one of them causes issues no matter what enclosure i use and i have access to Orico, Ice and Inateck (which supports SSD too) and the same bad drive causes a beach ball and i have to force shut down to use the mac or its useless, believe me i waited over 30 mins while at lunch only to return and see a beach-ball, now im gonna contact seagate support about it

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