My Mac Mini 2018 is running entirely on external TB3 SSD. Perfectly.

Discussion in 'Mac mini' started by pejx72, Apr 4, 2019.

  1. pejx72 macrumors newbie

    Jun 20, 2017
    I have my ideal setup now: A Mac Mini i5 (2018) running with everything on an external Thunderbolt 3 SSD 512GB.
    Everything very smooth. Getting SSD speeds of around 1700/1700 (read/write).
    No hitches. Easy setup.
    I did this to avoid worry about wearing out the internal SSD before I am ready to buy a new Mac (I keep my hardware for a long time). If anyone has any questions I'm happy to oblige...
  2. adamk77 macrumors 6502a


    Jan 6, 2008
    What do you keep on your internal SSD? (serious question).
  3. Stephen.R macrumors 65816


    Nov 2, 2018
    I’m guessing, nothing.
  4. adamk77 macrumors 6502a


    Jan 6, 2008
    Ha :)

    This brings back memories.

    My first SSD was back in 2008. It was still the early years, and I paid a hefty price of about $500 for the Intel X25-M G2 160 GB SSD (a flash from the past, here's a review by AnandTech

    I removed the optical drive from my 2008 Unibody MBP and put the SSD in its place. I remember being blown away by the speed. I was giddy opening all my applications at the same time, marveling at how fast everything launched (these awesome quality videos I made here and here at stunning 240p).

    I bought it before TRIM arrived. And I did whatever I could to reduce the writes cycles on the SSD. I placed all my /Users/* directories on the internal platter HDD and had just the OS and apps on the SSD. I even remember running a special utility that prevented the OS from writing the state to disk when it went into sleep mode.

    That drive is still going strong on an old Thinkpad, running Linux and working as my personal Git (version control system for tracking changes) and file server (external HDD for file).
  5. Stephen.R macrumors 65816


    Nov 2, 2018
    I got my 2011 MBP17 with a 128(0?) Gb ssd from factory and it’s still in use (albeit swapped to the optical bay, new WD Green (or is it blue?) in the main drive bay) but definitely showing it’s age.

    I’m of the opinion that if the internal drive suffers from use to the point it’s not practically usable then is the time to swap to an external (assuming the machine is still usable otherwise). But then I also buy my machines as company assets so my mini may end up “relegated” to home server duty (currently the 2011 MBPs job) early if there is a nice spec Mac Pro around in 2020.
  6. F-Train, Apr 4, 2019
    Last edited: Apr 4, 2019

    F-Train macrumors 65816

    Apr 22, 2015
    NYC & Newfoundland
    I don’t really understand why someone would purchase a 2018 mini and then spend additional funds to save the internal SSD from wear.

    If I wanted to do that, I think that I’d just purchase an older mini for day-to-day computing and reserve the 2018 mini for work for which it’s needed.

    Completely by accident, I wound up with a 2014 mini in addition to a 2018 and have done just that:
  7. user_xyz macrumors regular


    Nov 30, 2018
    Please describe how you set it up??

    i.e., Special install, etc
  8. LCC0256 macrumors member

    Dec 5, 2017
    Martinez, GA. USA
    This is a very interesting thread to me. I keep my Macs for a long time also. Upgraded my 07 iMac my 2010 MBP and my 2012 MBP with SSD's and max RAM to prolong their lives - all 3 are still highly functional for me. (07 for web browsing and housing master iTunes audio library, 2010 as the media server for videos for my AirPort Extreme based home network and the 2012 as my workhorse computer for my sub contracting business. I have wanted to purchase i7 2018 Mac mini with 16 GB RAM & 256 GB SSD (with larger external Thunderbolt SSD for additional storage to replace the 07 and 10) but it is not in the budget yet. Hoping the 3 other Macs hold up another couple of years. But my next Mac purchase is DEFINTITEY going to be a 2018 Mac mini.
  9. FreakinEurekan macrumors 68040


    Sep 8, 2011
    Eureka Springs, Arkansas
    So... you saved the $200 upgrade to 512GB internal, and spent however much on a TB3 external, in order to avoid "Wearing out" the SSD? How many decades are you expecting the Mac to run?

    ¯\_(ツ)_/¯ Vaya con Dios.
  10. chabig macrumors 603

    Sep 6, 2002
    I doubt he has a Thunderbolt 3 SSD. The smallest Samsung X5 Thunderbolt 3 SSD is 1 TB and it costs $500 (which isn't unreasonable). He's probably just saying that because of the shape of the plug. I bet it's a USB drive plugged into a USB-C port.
    --- Post Merged, Apr 5, 2019 ---
    It's easy.

    1. Plug in an external drive, and format it as APFS.
    2. Clone your system to the drive using CCC, Disk Utility, or SuperDuper.
    3. Set that drive as your Startup Drive in System Preferences.

    Alternatively, you could do a fresh install of macOS on the SSD and build your system from scratch.
  11. Fishrrman, Apr 5, 2019
    Last edited: Apr 5, 2019

    Fishrrman macrumors P6


    Feb 20, 2009
    The OP can't be serious (well, he either is serious, or he's a troll).

    Nobody on this forum has the experience I have in booting/running Macs from external drives. I've been doing it since the days of the Macintosh SE (1988), all the way up through my 2012 Mini -- which I just retired a couple of days ago.

    I booted and ran my 2012 Mini from an SSD in a USB3/SATA docking station from the day I took it out of the box in January 2013 (the Mini itself had an internal 5400rpm platter-based drive). It always ran great, right up to its final day of regular operation as my "main" Mac (it will live on as my "2nd Mac" on the other table).

    But when I got my 2018 Mini (i7/16gb/512gb), I knew it was time to take advantage of the superb speeds offered by the internal SSD.

    So I set up the internal SSD with 4 partitions, ALL of them (including the boot partition) running under HFS+. No APFS on this 2018 Mini. I might be the only user in the country with one running this way.

    Having said that, the speeds of the internal drive are FAR faster than the OP gets with his external X5:
    18 Mini Speeds.jpg
    Since you "keep your hardware a long time", by the time you DO give up the 2018 Mini, it will have long been superseded in power by newer Macs. Whether the internal drive is "used" or not will make little difference.
    You might be the only Mac user there is who is "saving it for resale"... ;)
  12. Stephen.R macrumors 65816


    Nov 2, 2018
    There are other brands that make TB3 SSDs smaller than 1TB - there's even an entire thread about DIY TB3 (e.g. M2 cases with a TB3 port).

    Even USB 3.1Gen2 won't support the claimed 1700MB/sec.

    Cool story bro.

    All reports I've seen say the write speed of 2018 Mac minis varies based on the size of the SSD installed, and only the 512GB and higher modules perform faster than the claimed 1700MB/sec for writes.
  13. zandorf macrumors member

    Oct 24, 2013
  14. treekram macrumors 68000

    Nov 9, 2015
    Honolulu HI
    It's not clear which Toshiba NAND chips Apple is using in their SSD's. It's probably their BiCS3 64-layer 3D TLC. If so, they have really high endurance - higher than the Samsung 970 Pro. These chips are not premium-priced chips. Corsair uses them in their MP510 line which Newegg sells for $90 for 480GB. The endurance for these NAND chips is such that if you have the 240GB model, it would be 100GB/day over TEN years; at 5 years (the warranty length) - it's .9 or 10 DWPD depending on the SSD capacity - for a 480GB model, it's 432GB/day. (These endurance figures are for the Corsair SSD since Apple doesn't publish endurance specs.)

    So, it kinda doesn't make sense to leave the internal SSD mostly unused except if you believe in the following scenario:
    - With at least some of the Macs which have the soldered SSD, if the SSD fails, the logic board won't work either. I don't know if this is the case with the 2018 Mini.
    - If you believe that using the SSD in normal fashion will significantly increase the chances of the type of SSD failure which causes logic board failure within a reasonable time frame (5 years or however long you believe your Mac should last without a major failure).
  15. IngerMan macrumors 65816


    Feb 21, 2011

    Are you running Mojave? I restored my 2017 MBP and had it in HFS+ not even realizing it. But when the latest Mojave update came out a few weeks back it would not update because I was not APFS. At least that is what it told me. I had to reformat in APSF and restore again for it to take the update.
  16. Dr. Stealth, Apr 5, 2019
    Last edited: Apr 5, 2019

    Dr. Stealth macrumors 6502a

    Dr. Stealth

    Sep 14, 2004
    SoCal-Surf City USA
    My 2TB X5 TB3 does pretty good speed-wise compared to the internal. Very happy with it.

    2TB X5

    Attached Files:

  17. EightyTwenty, Apr 6, 2019
    Last edited: Apr 6, 2019

    EightyTwenty macrumors 6502a

    Mar 11, 2015
    That’s a silly reason to use an external SSD, in my opinion.

    If you needed a bigger solid state drive and it’s cheaper than the upgrade directly from Apple, fine. But the internal SSD will likely outlast the usefulness of your machine by quite a lot.
  18. pejx72, Apr 6, 2019
    Last edited: Apr 6, 2019

    pejx72 thread starter macrumors newbie

    Jun 20, 2017
    I really hear those of you who say this is unnecessary, what I am doing! But it just makes me feel better. I guess I have a little bit of OCD ;-) I don't like the idea that my new computer is wearing out a bit every time I download a couple of GB here and there to play around with stuff. I know the SSD probably will last longer than the Mac Mini itself, but because of the nature of SSD wear, and because the SSD in Macs is soldered in and non-replaceable, I just *feel* better knowing that I am only wearing out a replaceable part now that I am running everything off an external drive. And, yes, to those who questioned it, I *am* using a TB3 SSD. It's the TEKQ one, it's almost as fast as the internal 256GB Apple SSD in my Mac Mini, and I paid GBP 186 for the 0.5TB version, which seemed fine to me since that's almost exactly the same as you would pay Apple to move from 256GB to 512GB...

    Thanks all for your comments - it's interesting to hear what others think about this.
  19. MacRS4 macrumors regular

    Aug 18, 2010
    London, UK
    You do not have any symptoms of OCD. Why people say such things cos they want to do something that makes little rational a bit odd.

    If it makes you feel better, go for your life, it doesn't really matter does it. You're effectively saying reality doesn't matter, cos what you do makes you feel better? It doesn't matter really does it.

    My machines all get a hammering - everything my 12" MB, my i9 MBP, a couple of iMP. They get used for what they're intended for. So far none of them have 'worn out'. Mind you, that's probably cos I replace them everytime a new model comes out :)
  20. jimthing macrumors 65816


    Apr 6, 2011
    London, UK (Europe, Earth, Space)
    Very correct. The larger the better. See here:

    In fact the 2TB has the best performance at BOTH writes & reads hitting ~2.6GB/s!
    And the space means you've got room to leave a decent 20% space for overhead going forward.
  21. Heat_Fan89 macrumors 6502

    Feb 23, 2016
    This is precisely the reason why I never went thru with a 2018 Mini upgrade and decided to stick with my 2012 Mini. I am not going to reward Apple by spending on another Mac when I know full well why they went with soldered storage.

    Here the OP had to spend even more money so as not to take the chance of ruining his or her computer. If the soldered SSD or T2 chip gives up the ghost, it’s an expensive motherboard replacement, if you don’t have Applecare (again spend more money) to protect your investment.

    All of this could have been avoided by using user replaceable SSD’s but Apple chose to lockout the user so as to spend more money on an upgrade or spend money for a workaround solution. My base 2012 Mini runs High Sierra just fine and the base 2018 Mini would make it scream but then i’d have to deal being shortchanged on storage and would need to spend more for a workaround solution.

    Compare the price of a comparable Intel NUC and Apple’s engineering choices and product pricing begins to raise eyebrows. So i’ll run my 2012 Mini and convert it to a Linux box when it’s no longer supported.
  22. Expobill Suspended


    May 30, 2018
    Awwww, sorry to hear that, what or where is the mini?
    I gave mine a 8 gb upgrade, im at 10 gb ram running majave faster, much faster
    Ya’know, those were the shiniest macs evah!
  23. adamk77 macrumors 6502a


    Jan 6, 2008
    I think it's absolutely fine. I wasn't judging. It's none of my business how you use your Mac. I was genuinely curious what you kept on your internal SSD.
  24. BasicGreatGuy Contributor


    Sep 21, 2012
    In the middle of several books.
    What you are doing is completely unnecessary and illogical. If you keep the internal drive at least 20% free, it will last many years.
  25. mlody macrumors 6502a

    Nov 11, 2012
    Windy City
    I would say you are a bit paranoid about it. Why don't you put your mac mini on a shelf and just look at it instead of using it? The moment you turn on the power, you are wearing down the machine - cpu, fan, transistors, capacitors, memory, storage etc but all of these are meant to last the life of the device.

    Like some others, I also have SSD drives from like 10+ years ago and they still work fine. I remember paying over $250 for 64GB Corsair SSD.

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