If you add an eSATA port to the iMac can it do RAID0 in an external enclosure?

Discussion in 'iMac' started by wirelessness, Aug 24, 2010.

  1. wirelessness macrumors 6502

    Joined:
    Jun 20, 2010
    #1
    I'm thinking of doing the eSATA mod and want to research what type of external drive options would then be possible.

    Mainly, can you do RAID0 with an external enclosure? If so how would the performance compare to using the two internal drive bays/ports to host the RAID0 boot drives?
     
  2. DannyBres macrumors 65816

    DannyBres

    Joined:
    Oct 30, 2007
    Location:
    UK
    #2
    As in with 2 external drive or RAID0 with the internal and external?
     
  3. mulo macrumors 68020

    mulo

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    Aug 22, 2010
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    Behind you
  4. DannyBres macrumors 65816

    DannyBres

    Joined:
    Oct 30, 2007
    Location:
    UK
    #4
    OWC will do it for you! Or a lo of B@lls and a dremel!
     
  5. wirelessness thread starter macrumors 6502

    Joined:
    Jun 20, 2010
    #5
    I would like to know if you could do RAID0 using a dual bay external drive enclosure and how that would perform compared to a RAID0 configuration using two of the dedicated SATA ports to attach the drives.
     
  6. Fat Fatster macrumors newbie

    Joined:
    Sep 3, 2010
    #8
    it's simple...

    Yes, have OWC add an eSata port. It only costs about $100. It is staggeringly stupid that the new iMac does not have one - it is really beyond belief.

    Next you want a "RAID0" external drive box. That box will have TWO drives in it (or possibly FOUR in some versions). The box itself entirely takes care of the RAID. In fact your Mac WILL NOT EVEN KNOW it is a RAID drive. It just looks like one normal drive.

    Makes sense?

    There is absolutely no way to have RAID "using the internal drive" or anything like that. It's a meaningless idea. RAID is a box, with a complicated RAID card, and also as an additional matter a couple of cheap hard drives. RAID has no relationship to the drive in your Mac or anything else in your Mac.

    Hope it helps!

    Furthermore, with your RAID box, you will be able to choose either RAID0 (speed) or RAID1 (security). (There is a switch on the RAID box to make the change.) Again that has utterly nothing to do with your Mac. Your Mac will not even know and have no way of knowing which mode the RAID box is running under.

    In answer to your other question you only need one connection (eg, the eSATA connection) to connect a RAID box. A RAID box is "one drive" overall, it only uses one cable. There is no way to use two cables, it is conceptually meaningless. Remember, a RAID drive is just "one drive" (even if there are two or maybe four physical raw drives inside the RAID box - that is something you never know about or deal with).

    In fact ... every RAID box made has both eSATA and FW800 connections. So, GO AHEAD and buy the RAID box of your dreams, and plug it in with a FW800 cable.

    Once you get used to it and like it, have OWC add a proper eSATA hole to your iMac. You can then change the cable from the FW800 cable to the eSATA cable.

    TIP: do not try to skimp on buying a RAID box. Get the one that is a bit more than you want to pay!
     
  7. DannyBres macrumors 65816

    DannyBres

    Joined:
    Oct 30, 2007
    Location:
    UK
    #9
    With a single Sata drive in an enclosure connected via eSata won't OS X be able to configure the external and internal in software RAID.
     
  8. wirelessness thread starter macrumors 6502

    Joined:
    Jun 20, 2010
    #10
    I was told by OWC that adding a multiple drive external RAID enclosure connected via eSATA in RAID0 will not improve performance the way two internal drives in RAID0 will. Reason being the internal drives each have dedicated SATA connectors and the external eSATA enclosure will only be working of one SATA port. To get the RAID0 performance increase you would need some sort of RAID controller card which the iMac obviously does not have. There is no reason not to do RAID1 for redundancy though.

    I was hoping to have 2 SSD drives connected to the eSATA port in RAID0 for a speed increase without having to go in the iMac case every time I wanted to increase the SSD size or potentially use more than 2 drives for even more speed. Unfortunately this will not be an option.

    I still intend to add an eSATA port and use that for either a single SSD drive for my Bootcamp or a multi-drive bay for RAID1 storage/backup. I have already added the two internal SSD drives in RAID0 which is great. To add the eSATA port I will have to abandon the nearly useless optical drive...
     
  9. FireWire2 macrumors 6502

    FireWire2

    Joined:
    Oct 12, 2008
    #11
    RAID0 kind of scary, why not a Five Drive hardware RAID5 for reliable storage
    Quad interface eSATA/FireWire/USB2.0
    Or simple eSATA

    These transfers up 250MB/sec

    As for the OD, you can always use the USB2.0 port

    FireWire2
     

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