SSD speed: Blackmagic vs AJA System Test crazy different!

Discussion in 'Mac Accessories' started by navaira, Jul 8, 2015.

  1. navaira macrumors 68040

    navaira

    Joined:
    May 28, 2015
    Location:
    Amsterdam, Netherlands
    #1
    Hello,

    I've got a Kingston SSD, SSDNow V300 120 GB, firmware SV300S37A120G. TRIM enabled via sudo trimforce enable.

    I've been wondering how fast it is because it doesn't really seem that crazy fast in comparison to my HDD. So I ran Blackmagic test and those are the results:

    Screen Shot 2015-07-07 at 11.04.36.png
    Not really insanely fast, right? But someone in another thread mentioned AJA System Test, so I ran that and here are the results:

    Screen Shot 2015-07-08 at 16.35.51.png
    Well colour me confused. 96.2 MB/s versus 496.9 MB write speed?! 236.4 MB/s vs 478.8? Is my SSD super slow and I should really invest in EVO 850 or is it as fast as it gets and I shouldn't waste money? Which of those tests is more reliable? Help!
     
  2. Weaselboy Moderator

    Weaselboy

    Staff Member

    Joined:
    Jan 23, 2005
    Location:
    California
    #2
    Here is the deal... that SSD uses a Sandforce controller and Sandforce controllers have lousy write speeds with incompressible data (like say an MP3). BlackMagic uses incompressible data for the speed test and AJA does not, and that is why you are seeing the difference.

    Most of the day to day drive usage is more dependent on read speeds anyway. What exactly do you use your computer for that you think you would even notice a slight improvement in write speeds? Unless you are doing some heavy lifting there that is dependent on fast write speeds, I can't see spending the money for another SSD.
     
  3. navaira thread starter macrumors 68040

    navaira

    Joined:
    May 28, 2015
    Location:
    Amsterdam, Netherlands
    #3
    I use the SSD as my system disk, it also has all the applications and my Photos library. That's it. So not really heavy lifting indeed. Thanks for the explanation, it makes sense. I use my computer also for audio/video editing, graphic design and music production, but the data for all that is on the HDD, not SSD, only applications themselves are on SSD.
     
  4. Weaselboy Moderator

    Weaselboy

    Staff Member

    Joined:
    Jan 23, 2005
    Location:
    California
    #4
    With that setup, I would be surprised if you could even tell the difference with a faster SSD. Looks like you are in good shape there. :)
     

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