Is the Hybrid HDD in retina iMac compare in speed to SSD in rMBP?

Discussion in 'iMac' started by letsudo, Dec 20, 2014.

  1. letsudo macrumors member

    Joined:
    Jan 19, 2012
    #1
    How does it compare to the 256 GB SSD and 512GB SSD?
     
  2. yjchua95 macrumors 604

    Joined:
    Apr 23, 2011
    Location:
    GVA, KUL, MEL (current), ZQN
    #2
    The Fusion Drive in the iMac is basically a 128GB SSD fused in RAID 0 with a 1TB or 3TB 7200rpm HDD.

    21.5" iMacs have the same setup but with a 5400rpm HDD.

    Fusion Drive:
    Reads: 600-700 MB/s.
    Writes: 350 MB/s on average.

    256GB SSD:
    Reads: 720 MB/s.
    Writes: 650 MB/s.

    512GB SSD:
    Reads: 730 MB/s.
    Writes: 720 MB/s.

    I went for pure SSD on all my iMacs because I needed pure speed and reliability.
     
  3. letsudo thread starter macrumors member

    Joined:
    Jan 19, 2012
    #3
    I would like to go with pure SSD also, and store all files on an external drive. What would be the price difference between the fusion and pure SSD? Do they have 21 inch retina too now?
     
  4. redheeler macrumors 603

    redheeler

    Joined:
    Oct 17, 2014
    #4
    The 256 GB SSD equals the 1 TB Fusion in price. Pure SSD with external storage is the way to go.

    No, the 4K 21.5'' will most likely show up sometime in 2015.
     
  5. yjchua95 macrumors 604

    Joined:
    Apr 23, 2011
    Location:
    GVA, KUL, MEL (current), ZQN
    #5
    Retina is only available on 27".

    1TB FD = 256GB SSD.
     
  6. letsudo thread starter macrumors member

    Joined:
    Jan 19, 2012
    #6
    Which storage though.

    I've heard that you need backup of storage too so I guess you need two externals? (4tb each?)

    ----------

    I heard that the retina iMac 27'' is really good deal. Would you agree with that?
    I heard that it is really expensive to buy a separate 27'' inch retina monitor to use it with a desktop computer so it's better to buy the retina iMac.
     
  7. redheeler macrumors 603

    redheeler

    Joined:
    Oct 17, 2014
    #7
    A 5K monitor from another manufacturer will cost as much as a Retina iMac. If you want that display it's the best deal there is right now.
     
  8. DeltaMac macrumors 604

    DeltaMac

    Joined:
    Jul 30, 2003
    Location:
    Delaware
    #8


    The fusion drive is two separate devices (SSD and HDD), but your system sees it as a single volume. The devices are not normally separately accessible, and a backup would be to one volume - there is only one volume in a fusion drive.
    The only reason that you would need two externals, would be if you want to keep two separate backups of your files, etc., which is not a bad idea, particularly for a business computer - but you don't need two backup drives simply because you know that there are actually two physical devices. They work as a unit, and backup sees one volume only.
     
  9. /V\acpower macrumors 6502a

    Joined:
    Jul 31, 2007
    #9
    I think he meant that if you have a 256GB SSD and everything else on external storage, you will still need another external storage to backup the SSD and the external storage. (because you will want at least another copy of every files, from the SSD and the external drive).

    If that is what he meant, the answer is "yes", he will need another external drive to backup EVERYTHING.
     
  10. /V\acpower macrumors 6502a

    Joined:
    Jul 31, 2007
    #10
    If the data on the first external drive you are gonna use as storage are important, then yes it is best to have another drive to backup everything.

    However, normally you will want your Time Machine backup drive to be bigger than the sum of all the drives you want to backup, or at the minimum be equal in size.

    256GB SSD + 4Tb of storage = you will need more than a single 4 Tb drive.

    And the ideal thing is having a bigger drive to make your backup, to be able to keep old deleted files and not just your current files.

    Personally I have a 1Tb Fusion drive (which is really more like 1.128 TB) + a 1 TB external drive for additionnal storage, and then a 3 Tb drive for Time Machine which backup both the internal and external drive at the same time.

    However, even having a 3Tb time machine backup, I still take measures to limit the backup space, like the fact that I don't backup the download folder (you can set this up in Time Machine), since I know that there is lots of big folders that will appear in this folder that I don't necessarily want to keep anyway. At the same time I know that when I download something and I want to keep it, I simply have to move it somewhere else and Time Machine will make a backup of it. Just with that I can save GB of space in my backup.
     

Share This Page