RAID0 becoming sluggish

Discussion in 'Mac Accessories' started by ColdCase, Mar 16, 2015.

  1. ColdCase macrumors 68030

    Joined:
    Feb 10, 2008
    Location:
    NH
    #1
    I've heard rotational drive data rates slow down as they fill up. At what point would you expect a disk utility RAID0 set with a pair of 2TB 7200 rpm drives become relatively sluggish? Just wanted to get a feel as I'm now seeing 230 MBps black magic scores on a 3/4 filled set where it was showing 360 MBps 6 months ago when new.

    Just don't want to chase a hardware problem, when thats just the way it is.

    SMART status shows no errors.

    Thanks
     
  2. matreya macrumors 65816

    matreya

    Joined:
    Nov 14, 2009
    #2
    I've got a pair of 4TB HGST NAS drives in RAID0 which is just over 75% full, and I get speeds of 300MB/sec....

    I have a set of 4 Toshiba 2TB in a RAID0 set, also just over 75% full and get 720MB/sec read, 590MB/sec write.
     
  3. chogue23 macrumors member

    Joined:
    Mar 16, 2015
    Location:
    Waco, TX, USA
    #3
    As mechanical drives fill up, the read and write speeds will be effected because the drive heads have to physically move farther to read the data. This happens to some degree on every single drive, but some brands will fare differently than others. A general rule is that if your drive is more than 3/4 full, it is time to consider upgrading, especially in a world with 4tb drives at around $120. Also you might consider getting a couple large external drives and compressing your less used files to them as a backup. This would keep your raid drives freed up and still have access to all your data.
     
  4. ColdCase thread starter macrumors 68030

    Joined:
    Feb 10, 2008
    Location:
    NH
    #4
    Yeah I have several storage boxes. I was just surprised that one had slowed down so much. The only real difference between them is how full they were. I wasn't sure if I should start looking for a hardware issue. The drives are seagate ST2000DM001 which are suppose to be pretty good when using recent firmware.
     

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