Multiple Raid arrays on 1 controller

Discussion in 'Mac Pro' started by avatarbe, Sep 2, 2010.

  1. avatarbe macrumors newbie

    May 27, 2009

    A quick question: Is it possible to have multiple raid arrays on 1 raid controller?
    I want to put 3 ssd in raid 0 AND 4 hard disks in raid 5 in my Mac Pro 2010.

    Is it uberhaupt possible to put 7 disks in a Mac Pro?

  2. Honumaui macrumors 6502a

    Apr 18, 2008
    depending on the controller ? usually yes you can do that so what controller do you have ?

    and yes you can get that many drives inside if you are creative if you mean 4 extra HDD inside it will be tight though and you want to make sure you dont split all off one power lead :) just to be safe the SSD wont be the issue its the other 4 ? you can do it but if you are talking 4 extra get a external case ? :)
  3. avatarbe thread starter macrumors newbie

    May 27, 2009
    The controller is the standard Mac Pro 2010 controller.
    And I dont mean 4 extra. Just 4 HDD, and 3 ssd. Would power also be an issue with 4hdd and 3ssd?
  4. Honumaui macrumors 6502a

    Apr 18, 2008
    no power would be no problem for that :)

    I thought the mac controller is 4 ports only ? and uses the backplane connectors in the stock location ?
    I really am not familiar and wait for others like nano or ? that might have experience with it but I am pretty sure this is the case with the card ?

    many of us just run cards like Areca or Atto in the mac instead

    for your SSD I would put them up in the optical bay ? 2 can fit easy cant see why 3 wont fit
    just get some Y adapters and come off the power in that area
    I have two SSD in my mac along with the other HDDD as others do here
    transintl makes some turn key solutions for you to choose from if that is easier ?

    I might say jump one off the sata port that is up their and get a card and jump the other two off a basic card that has some internal ports on it ? or external ports and just run the wire back inside ?
    since I am pretty sure the raid card is for the 4 HDDs only ? but again I am not going to say for sure cause I do not know for sure :) so wait for the next person in to make sure :)

    I am pretty good with setups and other stuff though but try to speak with experience rather then hearsay :)

    also not sure if you already have it or not ? but if you dont have it look at other solutions ? if you have it enjoy it then :)
  5. jedijoe macrumors 6502


    Oct 13, 2005
    Boulder, CO
    There are only 6 SATA ports on the MacPro, 4 sleds and 2 optical bays. To do 7 drives you would need a PCIe controller card.

    Mac OS X itself only supports Software RAID-0 and RAID-1, no RAID 5. RAID-5 in software is generally a bad idea due to its high compute requirements (especially during writes)

    Also keep in mind that 3 SSDs in RAID-0 on the Mac Pro SATA controller can be approaching the I/O bandwidth limits of the controller itself (
  6. mackenziemac macrumors newbie

    Aug 20, 2010
    Ive always wondered how SSD would perform in raid 0, let me know what you do!
  7. avatarbe thread starter macrumors newbie

    May 27, 2009
  8. nanofrog macrumors G4

    May 6, 2008
    From a techical POV, Yes you can do this.

    But it won't be possible via the SATA controller on the logic board, as it's only 6x slots, has a bandwidth limitation of ~660MB/s, and cannot handle RAID 5.

    So you'd need a fast, bootable RAID card, and some other odds and ends.

    Backups will need to be done externally, and it would be a good idea to use an eSATA card as the data transfer method. Newertech makes a nice pair of cards (standard 2 port 6.0Gb/s, and another 2 port 6.0Gb/s with Port Multiplier support).

    Please note that there are cards that are much cheaper that claim to run RAID 5. What I'm talking about, are software implementations = are not suited to parity arrays due to the write hole issue. That takes a hardware solution (just can't be fixed in software).

    As a result of the hardware you'll need to really do what you want (no throttling, boots OS X,...), the above list is a bit over $800 before buying a single disk. But it will be a proper installation for both striped SSD's and a RAID 5 mechanical array. :)
  9. Transporteur macrumors 68030

    Nov 30, 2008
    Just out of curiosity, what transfer rates does the 1880i provide?
    I'm a little surprised at the 800MHz processor in combination of 8 SAS/SATA 6Gb/s ports. 540MB/s x 8 = 4.3GB/s, which seams a little too much for that small processor.
    Their 1680ix with 16 3Gb/s ports (so about the same theoretical throughput) clocks with 1.2GHz.
    Newer processor generation?
  10. nanofrog macrumors G4

    May 6, 2008
    Take a look here, and here (benchmarks currently available). :)

    As it happens, the IOP348 began life at 800MHz, and it's SATA performance was dismal when it first came out (what most systems use). It took a firmware revision to get it to acceptable levels, and Intel then pushed the clock frequency to improve matters further. What helped their adoption at all, is the fact they're cheaper than their 12x1ML counterparts (also 800MHz, SATA only), and can attach more disks via SAS expanders (also lowers costs, as there's fewer controllers and systems; think SAN implementations).

    There's also more detail as to what's going on in the first link, so enjoy. :D
  11. avatarbe thread starter macrumors newbie

    May 27, 2009
    Thanks alot, this is very helpful! I will look into this, and I'll postback when my setup is done (can take a while, I dont have my macpro yet...)
  12. avatarbe thread starter macrumors newbie

    May 27, 2009
    a question about that raid controller you are talking about:
    Am I able to put the two arrays (3x ssd, 4xhdd) on that controller? If yes, i suppose I don't have to order apple's raid-controller?
  13. Honumaui macrumors 6502a

    Apr 18, 2008
    yes the 1880 can do that easy and will run circles around the apple one !
  14. nanofrog macrumors G4

    May 6, 2008
    Yes you can, and you actually have to do it that way, as there's no choice (not enough bandwidth on the ICH for the SSD's, and the MP cannot offer RAID 5 without a PCIe card).

    No, you don't need this card (couldn't do what you need anyway; slow and too few ports). Besides, it's a Pile of Junk, so get it out of your mind.
  15. avatarbe thread starter macrumors newbie

    May 27, 2009
    Thanks, I think I know all i need to know now to make a kickass system :)

    I heard the fan of the ARC 1880i makes a lot of noise, but i suppose it will not be that bad.
  16. nanofrog macrumors G4

    May 6, 2008
    It shouldn't be that bad, but worst case, you can always swap it out (should be the same fans as their other cards).

Share This Page