Slow AGILITY 3 in mac mini mid 2011

Discussion in 'Mac mini' started by volodymyrqa, Feb 12, 2012.

  1. volodymyrqa, Feb 12, 2012
    Last edited: Feb 12, 2012

    volodymyrqa macrumors regular

    Joined:
    Apr 14, 2011
    Location:
    Kyiv, Ukraine
    #1
    Guys,

    recently i've installed OCZ Agility 3 60 GB SSD into my mac mini mc816.
    Speed increase is noticeable after ordinary HDD.

    But i was expecting faster write speeds. Blackmagic test showed me 75mb per second. I also tried manual file copy/paste on SSD and speed was like in blackmagic. AJA test is not even starting ( don't know why ).

    SSD is connected via SATA3 as you can see on a screenshot. Is there any way i can increase write/read speeds?

    TRIM is enabled ... if it means something to you )

    P.S. This is my first SSD, so please, try to understand me, i'm ordinary guy without this specific hardware knowledge :)
     

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  2. philipma1957, Feb 12, 2012
    Last edited: Feb 12, 2012

    philipma1957 macrumors 603

    philipma1957

    Joined:
    Apr 13, 2010
    Location:
    Howell, New Jersey
    #2
    down load xbench run the disk test only and show us results. many times the problem is the test program. note my score on an intel sata II 210 write 190 read and random 55 write 14 read. xbench link


    http://xbench.com/ just need to click the disk test


    compare my intel ssd connected via thunderbolt to my time machine connected via fw800.

    notice the 4k random numbers are terrible for the fw800.

    4k random numbers are very important for your boot/app drive


    those other numbers only are important if you clone the drive. and since the drive is only 60gb the drive will clone in well under an hour . let us know what your random 4k read write are via xbench


    here is another link for you


    http://www.anandtech.com/show/4346/ocz-agility-3-240gb-review


    your drive has 10k iops random 4k read and 50k iops 4k random write.


    look at this review on my 600gb intel


    http://www.anandtech.com/show/4244/intel-ssd-320-review


    my random 4k read is 40k iops and random write is 23k iops max.

    basically you should get numbers like 35MB/sec write and 15MB/sec read for your random 4k xbench scores that sound and reads way slower then the 500MB/s 400 MB/s sequential numbers but hdds give .8MB/s read and .5MB/s write so you are up to 50 x faster on short read writes. anytime the random 4k numbers are 10MB/s or more they kill all spinning hdds in any test except a long clone of the drive.
     

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  3. volodymyrqa, Feb 12, 2012
    Last edited: Feb 12, 2012

    volodymyrqa thread starter macrumors regular

    Joined:
    Apr 14, 2011
    Location:
    Kyiv, Ukraine
    #3
    First of all thank you very much for your answer and suggestions :)

    My xbench disc test results ( is it ok? ^_^ ):
     

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  4. philipma1957, Feb 12, 2012
    Last edited: Feb 12, 2012

    philipma1957 macrumors 603

    philipma1957

    Joined:
    Apr 13, 2010
    Location:
    Howell, New Jersey
    #4


    well your random 4k writes are 119 MB/s very fast

    your random 4k reads are 25MB/s also fast



    http://en.wikipedia.org/wiki/IOPS


    and a conversion site

    http://www.ssdfreaks.com/content/599/how-to-convert-mbps-to-iops-or-calculate-iops-from-mbs



    so this means your 120MB/s / 4 = 30 x 1024 = 30000 iops for random 4k write

    and 25MB/s /4 + 6.25 x 1024 = 6400 iops for random 4k read



    this is 2x the speed of my intel 320 600gb


    also more then 100x the speed of an hdd for writes and more then 50 x the speed for hdd reads.

    I would not be worried about it. test in a week to look for slowing
     
  5. volodymyrqa thread starter macrumors regular

    Joined:
    Apr 14, 2011
    Location:
    Kyiv, Ukraine
    #5
    Wow :) OK ! Thank you ! :)

    too bad that this forum does hot have 'Thank you' button or similar.
     
  6. volodymyrqa thread starter macrumors regular

    Joined:
    Apr 14, 2011
    Location:
    Kyiv, Ukraine
  7. paulrbeers macrumors 68040

    Joined:
    Dec 17, 2009
    #7
    First off, Black magic uses incompressible data which Sandforce drives do not do well on for benchmarks (unless you are buying a Vertex 3 Max IOPS drive).

    Secondly, last I knew, 60GB drives have the fewest memory chips of any SSD which means you have less bandwidth. Most of the time the 240GB SSD's are the fastest because they have the most memory chips (think of it like single vs dual channel memory).

    So really, for a 60GB drive using asynchronous nand chips, your numbers are about right. If you want a really fast drive that all benchmrks are impressive, go with a 240GB drive w/ Toggle Nand. Unfortunately these will cost you in the realm of $400, sooooo....
     

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