Crucial MX500 & TRIM

Discussion in 'macOS High Sierra (10.13)' started by Hexley, Jun 3, 2018.

  1. Hexley, Jun 3, 2018
    Last edited: Jun 3, 2018

    Hexley macrumors 6502a

    Jun 10, 2009
    macOS: 10.13.14
    Model: Late 2011 13" Macbook Pro Core i7 8GB 1600Mhz DDR3
    SSD: 1TB 2.5" Crucial MX500
    Format: APFS
    Used Space: Less than 0.5TB
    Blackmagic Read: 507MB/s
    Blackmagic Writes: 450MB/s
    Turn on to login while 100% charged and plugged: Less than 16 seconds

    Hi! I did a fresh install of HS and noticed that TRIM Support is "No".

    Should I turn TRIM Support to "Yes"?

    On an unrelated note I noticed really weird read/write speeds via USB 2.0.

    Copying from 4 different IDE drives housed inside a Firewire 400 (400Mbs/s) enclosure one after another onto the Mac I got write writes of >40MB/s. As expected.

    Copying to a 20TB WD My Book Duo RAID0's USB 3.0 (5Gb/s) from my Mac's USB 2.0 (480Mb/s) got me read/writes of 15-25MB/s. That is surprising as I was expecting ~48MB/s from reading from a SSD to writing to a RAID0.

    It took me 8-9 hours to copy over 404.4GB of data instead of 2.4 hours. :-|
  2. FNH15 macrumors 6502

    Apr 19, 2011
    In macOS, TRIM support for non-Apple SSDs is turned off by default. If your SSD supports TRIM (like yours does,) then you should turn it on.

    As for USB 2.0 speeds, I'm afraid I won't be much help to you there, as its been quite some time since I interfaced with any USB 2.0 media.

    Hope that helps!
  3. Darmok N Jalad macrumors 65816

    Darmok N Jalad

    Sep 26, 2017
    Yes, absolutely enable TRIM. You'll see better long term performance.

    As for the USB 2.0 question. Found this on wikipedia:
    I suspect that since your device is designed for USB 3.0, it might struggle to communicate over the older, slower USB 2.0 bus.
  4. Hexley thread starter macrumors 6502a

    Jun 10, 2009
    I've observed in my 2010 13" Macbook Pro that USB 2.0 was able to be sustained at ~48MB/s

    So no issues with HS, APFS & TRIM?
  5. Darmok N Jalad macrumors 65816

    Darmok N Jalad

    Sep 26, 2017
    I wouldn’t even use APFS, to be honest. Apple has yet to really sell me on the benefits over HFS+, especially on non-Apple SSDs. You can bypass the APFS conversion while installing HS.
  6. h9826790 macrumors G4


    Apr 3, 2014
    Hong Kong
    You should turn ON TRIM. It's not just performance issue, but without TRIM, the SSD will ware out much quicker due much more unnecessary internal data movement (when the SSD onboard controller doing some internal "house keeping").

    For your info, my MX500 2TB is working flawlessly with TRIM enabled.
    MX500 2TB.png

    However, if you experience very slow boot after enabling TRIM. I suggest you go back to HFS+ rather than disable TRIM.

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