SATA III and Raid

Discussion in 'Mac Pro' started by jim.bright17, Oct 19, 2012.

  1. jim.bright17 macrumors member

    Joined:
    May 28, 2010
    Location:
    Alberta
    #1
    I have a 2010 mac pro and I would like to get a SATA III SSD to boot from. I also have 2 3TB disks in raid 1 right now for my media library but since that is running out of room (Only 3 TB usable) I would like to get another 3TB disk and put them in raid 5 for 6TB of usable space as well as protection from 1 disk failure (Correct?). Ive been looking for a card but cant really find anything that will boot. Looking to spend around $300-$400 on a card + SSD. Any suggestions? Not extremely educated on the topic so any help is appreciated.
     
  2. Designer Dale macrumors 68040

    Designer Dale

    Joined:
    Mar 25, 2009
    Location:
    Folding space
    #2
    The system bus on this machine is sata 2, so you can't get sata 3 speeds out of it. That set aside, using an ssd for the boot drive will speed things up quite a bit. Just get a sata 2 ssd.

    Can't help with the raid part.

    Edit: Other World Computing has bootable ssd cards that use the expansion slots in the Pro. Here's the link.
    OWC

    Dale
     
  3. hfg macrumors 68040

    hfg

    Joined:
    Dec 1, 2006
    Location:
    Cedar Rapids, IA. USA
    #3
    For best performance on your boot drive, get 2 matched smaller SSD drives and configure them as a RAID-0 array. You will probably have better overall performance than any Mac Pro single SATA-III solution (PCIe bus card)
     
  4. derbothaus macrumors 601

    derbothaus

    Joined:
    Jul 17, 2010
    #4
    Yes but you cut into your allowable bandwidth quite heavily to do so. A PCI card can side step the 650 MB/s chipset limitation. Unless you don't need any more transfer in each direction.
     
  5. nanofrog macrumors G4

    Joined:
    May 6, 2008
    #5
    The Areca ARC-1213 4i will do what you want, and fit your budget.

    As per configuration, you could run the SSD from it (boots under EFI once you flash the firmware) + 3 member RAID 5, or run the SSD from the empty optical bay (best choice IMHO), leaving you one port available for expansion in the future.

    You will need an adapter to use the internal HDD bays though, which will set you back another ~$130 (will be the case with any 3rd party RAID card in your MP). Correct adapter kit for your machine for use with MiniSAS based connections on the RAID card.

    Granted, the latter option (SSD in the empty optical bay) would have a SATA III disk on a SATA II port, but keep in mind, that booting relies on random access performance, not sustained throughputs.

    Since the random access performance will not saturate the SATA II bus, it's quite viable for an OS disk (sustained throughput tops out at ~275MB/s for a single SATA II port, so long as the controller isn't pushed past it's design limit of ~660MB/s from all ports combined).

    This does not improve random access, and in fact, can have a negative impact.
     
  6. hfg, Oct 19, 2012
    Last edited: Oct 19, 2012

    hfg macrumors 68040

    hfg

    Joined:
    Dec 1, 2006
    Location:
    Cedar Rapids, IA. USA
    #6
    Well, I am not getting anywhere near 650 MB/s with anything I have tried in my 2008 Mac Pro (at least not using BlackMagic Disk Speed Test).

    I have tried combinations of:
    OWC 3G SSD drives,
    Crucial M4 6G SSD drives,
    internal SATA-2 interfaces,
    and a PCIe Velocity SOLO X2 SATA-3 card.

    These readings were with the BlackMagic Test program (5GB setting).

    Write / Read (MB/s) Results:

    258 / 503 ... M4 on PCIe
    245 / 270 ... OWC on PCIe
    408 / 337 ... RAID-0 OWC internal SATA
    204 / 263 ... OWC internal SATA

    I believe the M4 on internal SATA ports were similar to the OWC readings.

    Is there something I can do to better these results on my Mac Pro?


    -howard
     
  7. nanofrog macrumors G4

    Joined:
    May 6, 2008
    #7
    How many of these SSD's were used in the stripe set?
     
  8. hfg, Oct 19, 2012
    Last edited: Oct 19, 2012

    hfg macrumors 68040

    hfg

    Joined:
    Dec 1, 2006
    Location:
    Cedar Rapids, IA. USA
    #8
    There were 2 3G OWC drives configured as RAID-0, mounted in the optical bay and connected to the motherboard SATA-2 channels. This is the configuration I am currently running with.
     
  9. beto2k7 macrumors 6502

    Joined:
    Jan 6, 2010
    Location:
    ::1
    #9
    In this link you can see my speeds for 2x OCZ Vertex 4 running in Raid0 using one Apricorn Velocity Solo X2 for each drive in slot 2 and 4.

    http://forums.macrumors.com/showpost.php?p=15936680&postcount=191
     
  10. hfg macrumors 68040

    hfg

    Joined:
    Dec 1, 2006
    Location:
    Cedar Rapids, IA. USA
    #10
    Yeah ... I saw that ... pretty impressive! :)

    Unfortunately, with a older 2008 Mac Pro I can't do that as I only have 1 available PCIe_2.0 slot (the other holds the video card). Slots 3 and 4 are only PCIe_1. I also had a no-boot issue with the Solo X2 card when I had another dual external eSATA card plugged into slot 3. Removing that card restored booting to the SOLO X2 card.

    I need eSATA for my external RAID-5 backup system, but I should be able to route the SOLO X2 auxiliary SATA channel out to the back panel to perform that task without the removed eSATA card if I return to using the X2 card.

    Do you also notice a delay in booting with the PCIe solutions? I guess the system looks for external drives after checking everything else.
     

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