How do I clean-install Mojave?

Discussion in 'Mac Basics and Help' started by Wingsley, Oct 23, 2018.

  1. Wingsley macrumors regular

    Mar 20, 2014
    Hi folks!

    iMac 14,3 (late 2013) 21.5-inch model; 2.9 GHz Intel Core i5, 8 GB RAM, 1 TB HDD, ext. SuperDrive
    USB 3 self-booting thumb drive with MacOS Mojave installer ready

    MacOS 10.12.6 Sierra
    (Time Machine backup)

    Microsoft Office 365 (2016)
    Adobe Creative Cloud (InDesign CC, Photoshop, Acrobat Pro, Illustrator, etc.)
    Final Cut Studio 3 (includes Final Cut Pro 7)
    iWeb 2009

    I followed the 9-to-5 Mac video instructions and now have a self-booting Mojave installer on a thumb drive.

    For years, I have had conflicts with old drivers and software cluttering my system and slowing it down. Malware scans and system cleaning has only been partially effective. It's been over decade since I last clean-installed the MacOS. I've put this off for too long. Now, it's time to clean-install Mojave. Out of options here. I takes over five minutes to boot up my system. Apps often launch slowly as well.

    I have plenty of loose ends and compatibility concerns, but I've decided to look at clean-installing and moving up to Mojave.

    Is there any special technique I have to use to clean-install off of my bootable thumb drive?

    I also have a Windows 10 installer disc here that I bought several months ago so I could run Windows-only software occasionally. Is there any special preparation I should be aware of for that?

    Thanks in advance.
  2. satcomer macrumors 603


    Feb 19, 2008
    The Finger Lakes Region
    Reboot and old down the Option key at the install boot up and it will ask to boot from!
  3. DeltaMac macrumors G3


    Jul 30, 2003
    There's really nothing wrong with doing a clean install - BUT, I think the biggest problem that you have right now, is that you are booting a modern macOS system from a 5400 rpm spinning hard drive. You may get some slight improvement with a reinstall, but you may also find out that it's not really worth your time to do a reinstall, if you stay with the spinning hard drive.
    If you were to do nothing else but change over to an SSD, you would immediately see a quite noticeable increase in booting speed, and launch of most any app will be obviously faster.
  4. MSastre macrumors 6502


    Aug 18, 2014

    I agree with getting an SSD, even an external, but try a clean install of Sierra on it first to see how performance improves. Final Cut Studio 3 is not going to work on Mojave, so you will want to keep a drive and OS that will allow you to keep using FC3 until you can transition to FCP X. I keep a couple drives with previous OS's on them to use with older programs, such as DVDSP.
  5. Fishrrman macrumors P6


    Feb 20, 2009
    Fastest, easiest, cheapest and SAFEST way to get "more speed" from a 2013 iMac with a platter-based hard drive inside:
    Get an EXTERNAL USB3 SSD, plug it in, and set it up to be the boot drive.

    The Mac doesn't care about whether it boots from an internal or external drive.
    An external SSD will boot and run circles around an internal HDD.
    You'll come back here and say, "I can't believe that could make so much of a difference!"

    I'd suggest a Samsung t5 or Sandisk Extreme.
    Important: you should remove any factory-installed software from these drives, then re-initialize them into Mac format (Mac OS extended with journaling enabled) using Disk Utility BEFORE you attempt an OS install on them. Things will go better that way.

    I'd do this:
    a. connect external USB3 SSD
    b. remove the factory software
    c. ERASE using Disk Utility
    d. NOW, boot from your USB flashdrive installer
    e. Install onto the SSD
    f. when done, begin setup
    g. when setup assistant asks if you wish to migrate from another Mac or drive, connect the TM backup and "aim" setup assistant at it
    h. select what you wish to bring over (I would choose everything), and "let 'er go". It may take some time.
  6. Mr_Brightside_@ macrumors 68030


    Sep 23, 2005
    Final Cut Studio 3 (includes Final Cut Pro 7)
    Are you sure this will work under Mojave?
  7. ChrisA macrumors G4

    Jan 5, 2006
    Redondo Beach, California
    Really this old software that is sitting there on the disk is slowing down the system? Have you verified this with Activity Monitor? I doubt that is the reason it is slow. What you need is a new SSD and more RAM. It is really hard to upgrade the disk in an iMac but the RAM is easy, upgrade to 16MB. If you are doing Adobe and Final Cut you need the RAM. 8 GB is not enough

    The disk is hard to upgrade. What I did is buy a Thunderbolt SSD. I have set up my iMac to boot from the external Thunderbolt SSD drive. Install your new Mojave there. Then boot off the new drive and do a Time machine backup.

    After the Time Machine backup completes re-format the internal drive and use it for data. The OS and all your apps and most of your working data will live on the Thundrbolt SSD.

    Actually what I bought was a Thunderbolt drive enclosure that hold two drives.

    As for the procedure, first install Mojave on the external SSD then use "migration assistent to move your data and apps.

    The other huge speedup would be to switch to Final Cut Pro X. The current version really is better.
  8. kiddk1 macrumors regular

    Aug 16, 2009
    I installed Mojave on my 2013 MacBook Pro it slowed the system down to a crawl I had to restore from Time Machine I should mention I am running a 5400 hard disk drive
  9. ChrisA macrumors G4

    Jan 5, 2006
    Redondo Beach, California
    A clean install of ANY version of Mac OS will slow the system down. Why? A new spotlight index has to be created. The system will take quite some time the scan the disk(s) and build an index. If you wait long enough it will finish.

    In your case, this is even worse because the disk being scanned is slow.

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8 October 23, 2018