troubleshooting notes I received from Crucial regarding my M4 512gb SSD

Discussion in 'MacBook Pro' started by kgallag1, Aug 31, 2012.

  1. kgallag1 macrumors member

    Oct 20, 2009
    Dorval, Quebec
    Thought I'd post a series of troubleshooting tips received from Crucial. Yesterday, my 512gb SSD completely quit responding, even to the point of not mounting on any drive or external case. I emailed Crucial/Micron, thinking the drive was defective. Apparently it likely isn't. I was using it as an OS drive, but upon replacing my 17" machine with a retina mac, I put the drive in an external USB3 case.

    Hello Kenneth

    Thanks for contacting us. The behavior you are describing is consistent with TRIM commands not executing on the drive (which may result from lots of writing and rewriting, especially OS installs, not done on the OS level). The accumulation of 'junk' data from file deletions, even reformats, basically clogs up the drive and reduces or sometimes even halts performance and can even dismount the drive. A secondary feature called Garbage Collection activates when the drive is powered, but has no data throughput, for an extended period, and does background cleanup on our SSDs which can make up for the lack of TRIM.

    If this is the cause of your drive's behavior, a period of idling the drive without any data being written or read actively will improve its performance. We recommend you perform this idle period on a desktop computer because it allows you to only connect the SATA power connection. However, a USB enclosure with an external power source will also work. A laptop computer will also work, but you’ll have connect the drive and navigate to the systems BIOS menu. (Please refer to your system manufacturer’s documentation on how to access the BIOS.)

    For laptops, we don’t recommended using a USB enclosure powered via USB; dedicated AC power is preferable. In addition, Apple laptop users must hold the Option key while they power on the system (with the SSD installed). This will boot the Mac to the Startup Manager screen. The Startup Manager screen works like the BIOS screen on a laptop, in that it gives the drive power without any data throughput. An alternative Apple method is to close all open programs (including background processes) after startup and idle on your desktop. Just power the drive and let it sit, preferably overnight, but even a few hours should improve performance if this is the cause of your drive's erratic performance, though full Garbage Collection takes 8-24 hours and should be resumed when you can be without that system for an extended period.

    If you have further questions, please visit the Crucial Community at For sales questions, try our online chat service at Our hours are Monday through Friday from 7 a.m. to 6 p.m. (Mountain Time). At Crucial, we are committed to providing high-quality products and reliable service and support.
  2. FuNGi macrumors 65816


    Feb 26, 2010
    Soooooo did you let your external SSD idle for long enough that all the garbage was taken out?
  3. kgallag1 thread starter macrumors member

    Oct 20, 2009
    Dorval, Quebec
    Doing it tonight, I have to buy a USB 3 external case with a power supply as I really don't want to go back into my PC again
  4. mac jones macrumors 68040

    Apr 6, 2006
    Interesting. They suggest you don't use these in USB enclosures. Care to guess why? How about a 50 to 100% failure rate. :D

    I had two that failed (512GB). Both I used in USB enclosures. The ones in non-plug n play setups haven't failed.

    The good news is that Crucial has very good customer support and replacements are easy enough.

    Anyway, these are probably the best bang for the buck, so.... it's always something?

    But you shouldn't be scared to use USB enclosures, it just may not be a good idea to keep doing it. You wouldn't want to anyway as that would be a total waste. As a matter of fact, I'm wondering why I did :confused:

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