New drive, downgrade to mavericks

Discussion in 'OS X Mavericks (10.9)' started by HDH, Dec 1, 2014.

  1. HDH, Dec 1, 2014
    Last edited: Dec 1, 2014

    HDH macrumors member

    Joined:
    Jun 4, 2009
    #1
    Currently working with Yosemite installed (on an HDD). Gonna format a new SSD, and copy everything over with TIME MACHINE. Do I need to install OSX after formatting or will the TIME MACHINE BACKUP do that for me?

    I have a couple of other questions:

    1) Should I downgrade to Mavericks cause of TRIM issues? Honestly I'm confused with the mixed comments regarding TRIM, third party SSDs, etc.

    2) Should I downgrade now before I time machine backup everything and then install back onto the SSD, or does it make sense to just do everything now, and in the end downgrade to Mavericks on my SSD?

    Sorry if some of my questions were stupid :)
     
  2. hallux macrumors 68030

    hallux

    Joined:
    Apr 25, 2012
    #2
    There is no TRIM "issue". I'm running TRIM just fine on 2 Macs with non-Apple SSDs, running Yosemite on both. The "issue" I guess is that you need to disable Kext signing in order to run the "modified" SATA driver. TRIMEnabler will do everything for you. The only thing you have to be conscious of is doing PRAM resets or major OS updates. All I'd do in those cases is disable TRIM, then do the update or PRAM reset then re-enable TRIM.

    I suppose there SHOULD be the caution that disabling Kext signing potentially leaves you open to some kind of malicious software modifying a major Kernel component.
     
  3. Weaselboy Moderator

    Weaselboy

    Staff Member

    Joined:
    Jan 23, 2005
    Location:
    California
    #3
    If your TM backup is on a locally attached drive, just attach that drive and option key boot to it. From there use Disk Util to format the disk then click restore. That will put the OS and all your apps and data back on the new drive. No need to reinstall the OS. Of course, since the backup was made with Yosemite, this will give you Yosemite.

    As far as TRIM, if you understand this caution and maybe print it out and save it somewhere, I think you are pretty safe with TRIM under Yosemite.
     
  4. HDH, Dec 2, 2014
    Last edited: Dec 2, 2014

    HDH thread starter macrumors member

    Joined:
    Jun 4, 2009
    #4
    Thanks for the reply.

    So should I just install my Samsung850Pro, format, then timemachinebackup copy, THEN disable the kext signing security setting, followed by enabling TRIM Enabler? Is that the correct sequence? (by the way on 10.10.1, if that makes a difference).

    I have another question too, isn't there a way to go back to Mavericks? I just don't get how I would then copy over everything from TimeMachine except for the OS.
     
  5. Weaselboy Moderator

    Weaselboy

    Staff Member

    Joined:
    Jan 23, 2005
    Location:
    California
    #5
    Yes.... exactly.

    When you do a restore from TM, you can scroll back in time to pick a restore point. So you could go back to when Mavericks was on there and restore to that point. However, and personal data added since that date would not be restored.
     
  6. sharon22 macrumors regular

    Joined:
    Oct 19, 2014
    #6
    I hope you post back after installing your Samsung 850 pro. I have been drooling over that model ever since it was released recently. I almost got an 840, until I saw the ad for the 850.

    I look forward to your comments on how it runs!
     
  7. HDH thread starter macrumors member

    Joined:
    Jun 4, 2009
    #7
    No other way to do this? I've changed quite a few things since I updated to Yosemite. :(
     
  8. Weaselboy Moderator

    Weaselboy

    Staff Member

    Joined:
    Jan 23, 2005
    Location:
    California
    #8
    The other way would be to erase the entire disk and reinstall Mavericks then manually move data back and manually set all your settings like you want. A lot of work if you have done a bunch of tweaking.
     

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