SSD just installed on Mac mini, NOW What??

Discussion in 'Mac mini' started by Alex78, Feb 24, 2014.

  1. Alex78 macrumors newbie

    Dec 22, 2013
    Hello Everyone,
    I Just installed a new Samsung 840 pro 256GB into my late 2012 i7 Mac mini,
    I have Mavericks on USB flash ready to install :D, But I have no idea how to deal with new SSD in Mac :rolleyes: , Do I have to go normally with installation like normal HDD?? or I have to do something to the SSD first (trim or format or ??)
    Do I need to enable trim for this particular this drive? is this should be before OSX installation or after? and how? :confused:

    Thank you dear savers :eek:
  2. scottsjack macrumors 68000

    Aug 25, 2010
    No difference between HDD and SSD installs that I know. In my case I installed to the OEM 1TB MacIntosh HD and cloned over the to SSD externally. After testing that the SSD would boot and work correctly I moved the OEM to the upper bay and installed SSD in the lower.
  3. Weaselboy Moderator


    Staff Member

    Jan 23, 2005
    Option key boot to your USB installer then once the recovery screen comes up use Disk Util to erase the new drive to Mac OS Extended (Journaled). Then quit Disk Util and click install OS. Once the install is done go ahead and setup your admin account.

    Then install the TRIM Enabler app and run it to turn on TRIM.

  4. jbarley macrumors 68040


    Jul 1, 2006
    Vancouver Island
    Just to avoid any confusion, does your interpretation of upper and lower agree with this picture, which BTW is Apples interpretation?
    There has been some confusion because when opening the mini you are viewing it upside-down.

    Attached Files:

  5. Alex78 thread starter macrumors newbie

    Dec 22, 2013
    All done, Thank you all :)
    Just one last thing, about the trim enabler app dos it have to be running all the time? if no how often should I check that trim still enabled? I mean dos the OSX disable trim by it self latter (if updates happened for example) ?
  6. Cloudsurfer macrumors 65816


    Apr 12, 2007
    There's a lot of discussion about wether or not trim is actually necessary on modern ssd's, as they have excellent internal garbage collection.

    Trim might actually interfere with this garbage collection which might decrease performance of the drive.

    I read somewhere that OSX actually tests if its built in Trim interferes with the drive's own garbage collection and if it does, it disables Trim automatically. But I'm not sure if that's actually true or not.

    Personally I would leave Trim for what it is and let the drive clean itself up.
  7. Gav2k macrumors G3


    Jul 24, 2009
    No it'll be enabled until you do a clean install.
  8. Weaselboy Moderator


    Staff Member

    Jan 23, 2005
    When you run that enabler app and tell it to enable TRIM, what it does is modify a system kext file to make TRIM work. After that you can quit the app.

    However, point updates (like 10.9.1... 10.9.2 etc) almost always turn TRIM back off because the modified kext is replaced. So you will normally need to run the app again and reenable TRIM after each OS update.
  9. Che Castro macrumors 603

    May 21, 2009
    Hey I enabled trim using a code I found here

    I did a restart and checked to make sure trim was enabled
    Today there was a new update to mavericks , do I need to enter the code again ?
  10. opinio macrumors 65816

    Mar 23, 2013
    If trim was disabled with the update then re-enable it. Use trim enabler or chameleon.
  11. theluggage macrumors 68040

    Jul 29, 2011
    I've seen some articles recommending 'overprovisioning' - fancy talk for adjusting the partition size in Disk Util to leave ~10% of the drive unallocated, to give the drive's internal housekeeping routines some spare space for 'wear levelling' etc.

    Its an adjustable option in the Windows-only utilities that come with the 840 pro - but I'm not clear that it does anything more than adjust the partition size as described above.

    Any thoughts on whether that is worth doing (it does mean sacrificing disc space)?
  12. Weaselboy Moderator


    Staff Member

    Jan 23, 2005
    OS updates almost always replace the kext file that you modified to enable TRIM, so yes you will need to run the enabler to hack the new kext to turn TRIM back on .

    My option is it is overkill. Just don't run the disk completely full all the time and you will be fine.
  13. Donka macrumors 68020


    May 3, 2011
    Garbage Collection requires idle time for the drive to do its own internal clean up. If you don't power down your Mini and have the 'Put drives to sleep when possible' unchecked in Energy Saver preferences then the drive will likely be able to complete its garbage collection when needed. It all depends on how you use your Mac. If you are active on it then shut down when finished what you are doing, the SSD will not likely have sufficient time to do its own clean up.
    In this instance you really want Trim enabled. Trim won't impact garbage collection on a modern SSD as the drive does its own clean up when idle. Trim is used by the OS when disk activities are actually happening i.e. when you delete files so garbage collection would not be running at this time.

    If you read on Crucial's website, they say you don't need Trim but they recommend ensuring you have periods when garbage collection can run and on the Mac they recommend unchecking the drive sleep option and then putting the Mac into sleep. Alternatively, boot into recovery partition and then do nothing - this provide power to the SSD but it is not being used for anything so garbage collection will kick in.
    One more thing, Windows 7 for example enables TRIM on all SSDs by default. If this would cause an issue with garbage collection, manufacturers would release drives specific to the OS they will be operating with.
  14. unconvinced macrumors newbie

    Dec 14, 2006
    Use trim. The read/write speeds of my 840 Pro were horribly crippled and sleep did not work properly until I turned on trim support. Also in a late 2012 mac mini.

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