Hardware RAID in new Mac Pro - yes/no?

Discussion in 'Mac Pro' started by funkahdafi, Mar 16, 2009.

  1. funkahdafi macrumors 6502

    Joined:
    Mar 16, 2009
    Location:
    Planet Earth, Old World
    #1
    Hi,

    I am currently using a 2006 mac pro with a 2 TB software RAID-0 array (two drives) and two additional drives without RAID. I am using one of the additional drives as my TimeMachine drive.

    I used RAID 0 simply to have higher performance.

    Now I am going to order the new Mac Pro this week and I was wondering to put in the RAID card or not. How much of a performance gain can I expect from the hardware RAID vs. software RAID? Other advantages other than that?

    I am also wondering if I should expand from RAID 0 to RAID 0+1 to gain redundancy in addition to performance. However, I would have to deploy 4 drives and thus would lose my TimeMachine drive. I am also not sure if this setup would support Bootcamp.

    What are your thoughts? Is it worth upgrading from software to hardware RAID? And if so, is the Apple RAID card a good choice (I know I will have to wait 4-5 weeks longer for delivery of my new baby)?

    Thanks
     
  2. Abulia macrumors 68000

    Abulia

    Joined:
    Jun 22, 2004
    Location:
    Kushiel's Scion
    #2
    I do pretty much the exact same thing on my current Mac Pro as well.
    Little to none. Software RAID at this point has little overhead or performance cost.
    The RAID card lets you use other RAID options -- such as RAID 5 -- that are unavailable via software.
    It has a battery on the card to complete any data transactions, thus safeguarding your data. External connectors for adding external RAID arrays.

    And, obviously, the card handles all RAID operation for better performance. Now the question is whether that performance is so much better than software RAID (unless you need something like RAID 5) to justify the price.
    This depends on your level of acceptable risk. Don't confuse fault tolerance with backup or recovery. RAID 0+1 or 1+0 is meant to maximize uptime against disk failure. Time Machine is more for user failure. ;)

    Does anything else on your network use TM or just the Mac Pro? You could create a volume on your RAID 1+0 array and point TM to that. TM does not have to be its own physical disk, IIRC.
    No, it would not.
    I would need to know more about what you use the machine for. Do you use this machine to make money? What is your time worth in the event of downtime? If you lose a disk will you lose business? These are the kinds of decisions that should factor into not only if you should get a RAID card but what your fault tolerance and data recovery strategy should be.

    Since you didn't share this information I'm going to just guess that you're a hobbyist and this is entirely for your own use. I'd do software RAID 0 for performance and keep your TM disk. It doesn't sound like the card would do anything for you.

    And don't forget Snow Leopard coming and ZFS.
     
  3. funkahdafi thread starter macrumors 6502

    Joined:
    Mar 16, 2009
    Location:
    Planet Earth, Old World
    #3
    Thanks Abulia.

    Actually I use my machine to make money, so data safety is very important for me. That's why I don't want to lose my TimeMachine.

    The main reason why I am looking at the RAID card is to gain performance. I know RAID is not backup, it just gives you the option to be back up quicker, in case only one drive fails. That's why I would *highly* welcome RAID 10, but only of the price-performance ratio justifies this. If there is little to no performance gain when using the RAID card, then I don't think I want to spend the money on it and wait 6 weeks before Apple can deliver this.

    How much of a performance gain will ZFS introduce?

    Does the Apple RAID card also allow for external connections?
     
  4. funkahdafi thread starter macrumors 6502

    Joined:
    Mar 16, 2009
    Location:
    Planet Earth, Old World
    #4
    One more question:

    Would striping four drives give me higher performance than striping two drives? Can this be done with software raid (without destroying the current raid set)?
     
  5. Tesselator macrumors 601

    Tesselator

    Joined:
    Jan 9, 2008
    Location:
    Japan
    #5
    More proformance? Yes! Something like this:

    2 drives = 190% Speed Increase.
    3 drives = 270% Speed Increase.
    4 Drives = 340% Speed Increase


    Without destroying the set? No, Not that I know of. You'll have to reformat.
     

Share This Page