What is RAID?

Discussion in 'General Mac Discussion' started by Groovsonic, May 19, 2003.

  1. Groovsonic macrumors regular

    Joined:
    Oct 4, 2002
    Location:
    Near Chicago, Illinois
    #1
    Hi!
    Dumb question: What is RAID? I know it has something to do with multiple drives, and I think splitting up data between the drives, but what is the purpose? Is it faster than having data stored on a single drive, or is it slower? Any information would be much appreciated.

    Thanks
     
  2. eyelikeart Moderator emeritus

    eyelikeart

    Joined:
    Jan 2, 2001
    Location:
    Metairie, LA
    #2
    RAID is an acronym for Redundant Array of Inexpensive (or Independent) Disks. A RAID array is a collection of drives which collectively act as a single storage system, which can tolerate the failure of a drive without losing data, and which can operate independently of each other.

    more information can be www.adaptec.com/technology/whitepapers/raid.html+raid+explanation&hl=en&ie=UTF-8]found here[/URL] on the different levels of RAID...
     
  3. Groovsonic thread starter macrumors regular

    Joined:
    Oct 4, 2002
    Location:
    Near Chicago, Illinois
    #3
    Thanks eyelikeart. Although the link was apparently broken, I basically traced your steps to find the infromation. It was interesting.

    Does anyone know how much faster accessing information would be with say a 3 or 4 drive raid than a single dirve? I want to know if it is worth investing in for my Music recording and video editing.

    Thanks
     
  4. Eniregnat macrumors 68000

    Eniregnat

    Joined:
    Jan 22, 2003
    Location:
    In your head.
    #4
    Your speed will be reduced, as 1/3 of all writing (in a 3 drive RAID) would be redundant and spread across the other two drives.- Simplistic and not completely correct, but close enough. It also depends on how your accessing your RAID drive. A NAS (Network Attached Storage- a kind of RAID) will be significantly slower because of the CAT5 bottleneck, a fiber line would be faster, SCSI2 still faster, etc...)
     
  5. LethalWolfe macrumors G3

    LethalWolfe

    Joined:
    Jan 11, 2002
    Location:
    Los Angeles
    #5
    I don't think it will speed up your audio editing, but for video it might under certain conditions. If you are editing DV you will see no improvement when using a RAID (current 7200RPM HDDs are more than fast enough to handle DV). If you are editing uncompressed video... well... if you were editing uncompressed video you'd already be using a RAID. ;)



    Lethal
     
  6. Groovsonic thread starter macrumors regular

    Joined:
    Oct 4, 2002
    Location:
    Near Chicago, Illinois
    #6
    Reallly? I must have misunderstood the idea. I thought it could be significantly faster because you are spreading data out over multiple drives and since all of the drives can be running at once, data can be pulled back faster. Is the only purpose of RAID for data protection?
     
  7. Groovsonic thread starter macrumors regular

    Joined:
    Oct 4, 2002
    Location:
    Near Chicago, Illinois
    #7
    So then I should just invest in one good FW HD instead of a few because I will see little to no improvement. Thanks for the info.
     
  8. LethalWolfe macrumors G3

    LethalWolfe

    Joined:
    Jan 11, 2002
    Location:
    Los Angeles
    #8
    Get a Firewire drive that uses the Oxford 911 chipset (if the drive uses it they'll advertise that fact) and you will be good to go for all yer DV storage needs. ;)


    Lethal
     
  9. Groovsonic thread starter macrumors regular

    Joined:
    Oct 4, 2002
    Location:
    Near Chicago, Illinois
  10. mc68k macrumors 68000

    mc68k

    Joined:
    Apr 16, 2002
    #10
    here's the best place if you want a full understanding of RAID and other HDD technologies.
     
  11. LimeLite macrumors 6502a

    LimeLite

    Joined:
    Mar 20, 2003
    Location:
    Los Angeles, Ca
    #11
    My understanding is that RAID doesn't spread data over multiple drives, it stores *the same* date across multiple drives. It can basically be used as an instant backup. When you save a document, it gets saved to all the drives that are linked. It's used more to backup stuff in case one drive fails.
     
  12. mc68k macrumors 68000

    mc68k

    Joined:
    Apr 16, 2002
    #12
    it can be. data can also be 'striped' or be split over multiple drives as one virtual volume.

    here's a brief description of the different types of RAID (levels) and what they do.
     
  13. destroyboredom macrumors 6502

    Joined:
    Dec 16, 2002
    Location:
    Washington, DC.
    #13
    I believe it all depends on what type of RAID you setup, while it is commonly used in servers for back up it is also used in a striping fashion. So your data is written to 2 drives at the same time. So basically if you d/l an Mp3 to a raid 0 (someone correct me if i'm wrong) configuration it will write half the data to one drive and half to another. I'm 99% sure this speeds things up a little (write and access time). The down fall is if one drive goes...bye bye data.
     
  14. patrick0brien macrumors 68040

    patrick0brien

    Joined:
    Oct 24, 2002
    Location:
    The West Loop
    #14
    -destroyboredom

    You're describing what sounds like RAID Lev. 0 - technically not RAID, as there's no 'R' (redundancy) in the array.

    That link above is one of the best, most concise table of RAID levels I've seen. I'm so scraping that.
     

Share This Page