How to move to RAID 0 System

Discussion in 'Mac Pro' started by msbc, Apr 25, 2015.

  1. msbc macrumors newbie

    msbc

    Joined:
    Jul 27, 2011
    Location:
    Melbourne, Australia
    #1
    I have a Tempo Pro PCI card with 2 Samsung 850 SSDs in my MacPro5,1. One SSD is my system-boot drive (10.10.3) the other is currently empty. What are the steps to make this a dual-SSD RAID 0 boot system? Would I have to do a fresh install or is there a way to enable RAID 0 across the 2 drives?

    Thanks,
    Mark
     
  2. OS6-OSX macrumors 6502a

    OS6-OSX

    Joined:
    Jun 13, 2004
    Location:
    California
    #2
    You really don't want your OS as part of the RAID. If you have HD slots 1-4 opened, place a 2TB HD in each slot. That will give you 8TB's @ a speed faster than a single SSD.
     
  3. Ph.D. macrumors 6502

    Joined:
    Jul 8, 2014
    #3
    This is a potentially complicated question to answer. Here's a quick go at it:

    Assuming you want to preserve the contents of your current boot drive, you likely need a third drive, e.g. a partition on a hard disk in a normal bay. Move everything to that via a cloning tool. Then wipe both SSD's, form them into a RAID 0 using Disk Utility, and re-clone your data back onto it.

    Good luck.
     
  4. IowaLynn macrumors 6502a

    IowaLynn

    Joined:
    Feb 22, 2015
    #4
    Only real reason to go through this is if the boot drive is too small - as a temporary stop-gap measure. It may look better in benchmark tests.

    Want speed performance, go for PCIe Express M.2 blade device with an adapter in another slot and use the Tempo for scratch or graphic library data.

    Never try doing this without a backup (or two) clone of the system to begin with.

    SoftRAID 5.x can convert from Apple RAID to SoftRAID; can do stripe-reads on mirrors and has some features that you might like.

    And yes I have done RAID0 for boot drive (going back to 15K SCSI and 10K Raptor), even a pair of Samsung 840's. With prices on Samsung 850 EVO 500GB as low as they are, or an OEM Apple blade...
     
  5. m4v3r1ck macrumors 68020

    m4v3r1ck

    Joined:
    Nov 2, 2011
    Location:
    The Netherlands
    #5
    1. Your OS will fly when using a RAID0 on the Tempo Pro PCIe SSD card with 2 SSD's, no problems at all when you at least have a very tight back-up sheme, because if one SSD fails you'll lose your entire OS!

    2. To have a 8TB RAID0 with 4 2TB HDD's will give you a fast RAID0 config, but the question is, what will your back-up scheme be for 8TB data when those drives fill up with data?

    3. Never had a 4 HDD RAID0 at SATA2 myself, so what are the speeds compared with a single SSD running at SATA3?

    Cheers
     
  6. hfg macrumors 68040

    hfg

    Joined:
    Dec 1, 2006
    Location:
    Cedar Rapids, IA. USA
    #6
    Prior to getting a 1TB Apple PCI blade SSD, I ran for a couple of years with a Tempo Pro RAID-0 boot disk using both 840 Pro SSDs and Crucial M4 SSDs. It worked fine and the speed was great (807 / 956 MB/s W/R per BlackMagic DiskSpeedTest). This is on a 5,1 2012 Mac Pro.

    I only switched to the Apple SSD in order to easily retain TRIM functionality in Yosemite.
     
  7. OS6-OSX macrumors 6502a

    OS6-OSX

    Joined:
    Jun 13, 2004
    Location:
    California
    #7
    4 HD's
     

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  8. velocityg4 macrumors 68040

    velocityg4

    Joined:
    Dec 19, 2004
    Location:
    Georgia
    #8
    That test is misleading it doesn't test IOPS performance. Sure it's faster with large files since it can read sequentially for the most part. Performance tanks compared with even a single SSD when processing thousands of tiny files each only a couple kb in size. Which is the major advantage of the SSD when it comes to dealing with the OS, boot times, load times, in servers when high IO performance is needed, &c.
     
  9. OS6-OSX macrumors 6502a

    OS6-OSX

    Joined:
    Jun 13, 2004
    Location:
    California
    #9
    How is it misleading when it answers the question asked?! The way the question was framed "so what are the speeds compared with a single SSD running at SATA3?" No where is it mentioned in this instance there is an OS attached. The question was detached from OP's inquiry. M4v3r1ck stated "Never had a 4 HHD RAID0 at SATA2 myself".
    Most users select RAID 0 for speed. Since the OP does not state what apps will be used it is not possible to say that the 2 SSD's will provide that unknown speed. Is the speed for apps only or also large files?
    So The entire thread is actually mute without knowing what apps will be used. Based on that alone there is know way of knowing what sized files will be moved.
     
  10. OS6-OSX macrumors 6502a

    OS6-OSX

    Joined:
    Jun 13, 2004
    Location:
    California
    #10

    To answer this question one would have to know how the drives are being used. First you don't let it fill up.
    1. If it is used for photography: a. what are the size of the photos? b. how many photos does it take to fill up 8TB?
    2. If it is used for video: a. Don't use it for storage of files that are no longer in projects. Use it as a drive for "working" files. b. All files from "past" projects are placed on external HD's. Two 4TB HD's can be used for storage/back up. c. Since it is RAID 0 and it fails, you have to replace the bad drive, rebuild and dump the files back on.
    3. Know what your particular genre entails. If you deal with Raw R3D files or uncompressed 10bit think if 8TB is even enough! One 2:30 uncompressed 10bit file is about 24GB!

    Anyway, the internal RAID 0 4HD's was years ago. I did not want to buy a R3D Rocket so I changed the RAID setup. Still RAID 0
     

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  11. m4v3r1ck macrumors 68020

    m4v3r1ck

    Joined:
    Nov 2, 2011
    Location:
    The Netherlands
    #11
    Thanks a lot for explaining the specific usage of your RAID0 system / backup scheme and sharing your test results. Always nice to have results from others to compare with my own!

    Cheers
     

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