3 Replies Latest reply: Apr 20, 2011 1:54 AM by Peace Freak!
Peace Freak! Level 1 Level 1 (145 points)

I just bought a 3 TB SATA 3 hard disk to use in an external case for backing up my computer and other files. I put it in a case and launched Disk Utility to find that it only shows up as having 800 GB available.

 

Is there some way I can get the size to be recognized correctly? Perhaps I need a SATA 3 case? Could someone get me up to speed?

 

Thanks in advance!


MacBook Pro 2.26 GHz, Mac OS X (10.6.5), 4 GB Ram
  • William Boyd, Jr. Level 6 Level 6 (10,515 points)

    Peace Freak! wrote:

     

    I just bought a 3 TB SATA 3 hard disk to use in an external case for backing up my computer and other files. I put it in a case and launched Disk Utility to find that it only shows up as having 800 GB available.

     

    This may not be the whole answer to your question, but this Web page

     

    http://www.hitachigst.com/tech/techlib.nsf/techdocs/D213A024C090CE9F862577D50026 00FC/$file/FinalHiCap_2.2TB_TechBrief.pdf

     

    discusses "high capacity" disks, those above 2.2TB.  The thing that makes me think that it's related to your problem is that 800 GB is exactly 3 TB less 2.2 TB.

     

    Did you partition that drive?  If not, what is the partition type?  That Web page suggests that a GUID partition map may be what you need.

  • Asatoran Level 4 Level 4 (2,535 points)

    Peace Freak! wrote:

     

    I just bought a 3 TB SATA 3 hard disk to use in an external case...I put it in a case and launched Disk Utility to find that it only shows up as having 800 GB available.

    Two thoughts: MBR can't handle 3TB so you'll need to repartition with GPT in Disk Utility.

     

    But my second thought is that your external case's firmware needs to be updated to handle larger than 2TB.  I recently was shopping for a 3TB external drive and noticed that all the "build-your-own" external cases only claimed to work with up to 2TB drives.  Hopefully there is an update for you case.  Otherwise you may need to buy a new case as well.

     

    In my situation, I relented and got a complete 3TB external drive from OWC rather than assemble my own.  I've always assembled my own before, but I was highly suspicious that my current (older) drive cases would not handle a 3TB drive.

  • Peace Freak! Level 1 Level 1 (145 points)

    Thanks for both replies.

     

    The problem was definitely the enclosure I was using.

     

    I went to my local computer store and they sold me an enclosure that did the trick. When I have time I will see if my older enclosure can be updated to handle 3 TB, but for now I needed to backup my data and get on with my work.

     

    Once again, thanks!