Promise Pegasus R4 slow read speed

Discussion in 'Mac Accessories' started by jshbckr, Jul 8, 2012.

  1. jshbckr macrumors 6502

    Apr 20, 2007
    Minneapolis, MN
    My Pegasus R4 is set up as a RAID 5 and I'm getting fast write speeds... they seem to fluctuate a bit, but averages around 475-500 MB/s.

    However, my read speeds seem to be around 200 MB/s. On the Black Magic Disk Speed Test, I get a LOT of X's for Read speed for various video formats. I'm using this for video editing, so this isn't good.

    Right now I actually have two 2TB drives in the R4, along with two of the 1TB drives that came with the unit. All drives are SATAIII 6Gb/s and 7200RPM. Could these slower speeds be because I have mixed capacities? It appears that the RAID is only using 1TB of the 2TB drives, anyway, so I don't feel like this should be the problem. Nevertheless, I have two more 2TB drives arriving (same brand and type as my current ones) and I'll see if that helps.

    Otherwise, does anyone have any idea what could be causing it or how to fix it?
  2. cheesenightmare macrumors newbie

    Nov 17, 2009
    I have exactly the same situation as you - R4 pegasus Read speeds half the speed of write speeds. Any discoveries since your post in July?
  3. theSeb macrumors 604


    Aug 10, 2010
    Poole, England
    Make sure you get the latest firmware from promise. It increased my read and write speeds quite a lot in black magic disk test up to the levels I was expecting and seen in reviews.

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