Previous 1 2 Next 19 Replies Latest reply: Nov 8, 2014 7:23 AM by den.thed
Hamper Level 1 (0 points)

I was dead set on getting an iMac and fitting it with a Crucial SSD, but I see how difficult that is. However, reading the blurb on Crucials website for their latest 1TB SSD, the M500, I noticed that they list the Mac Mini as an option and that nearly is the iMac so I've looked into it and the process is a lot less daunting. However there apears to be two HDDs bays in the tiny box, not sure why Apple did that as it's meant to be a small box, but there we are. My question is which one do I put the SSD into, I've seen a video where the most immediate one, readily accessed through the opening on the bottom, is acceptable, but what of the other?


How does OS X treat the second HDD, is it some kind of internal Time Capsule? How does it show up in OS X, as a separate partition? What happens if the new HDD/SSD is larger than the other? Why are there two in the first place? I also didn't glean any info from the product page on the Apple website that points to there being two HDDs.


Anyway, I think the new 2012 Mac Minis are capable of taking the M500 from Crucial, although I read their speed is taken down a peg to SATA II because of the enforced 3Gbps interface, is this true?



  • John Lockwood Level 5 (7,235 points)

    Both drive bays in the Mac mini are functionally identical. The one you use will depend on which bracket and cable you have.


    The Mac mini has SATA III (6Gbps) interfaces.


    As standard the Mac mini will treat two internal drives as two separate drives, e.g. one to boot from and one to store data. You can either configure them with software RAID, or use Apple's 'Fusion' scheme to make an SSD and a traditional hard disk in to one big drive with it automatically moving important files to the faster SSD.



  • Hamper Level 1 (0 points)

    Thanks for your reply. I am not a big fan of multiple HDDs, I like to have one only. I would swap out the easiest to reach one for the M500 and use it as my main drive, the other I suppose for emergencies. Unless I could use it as a mirror, so I could have TC working on it, would that work?


    Also, I read that TRIM support is not available for 3rd party SSDs on iMac's, is that the case for the Minis as well? I also read that the fan goes mental when having installed a 3rd party SSD in an iMac, both reasons why I am going to avoid doing that.



  • tbirdvet Level 4 (2,845 points)

    I have a new 2012 Mini and removed the stock 1TB hard drive and replaced with 512GB SSD.  When accessing the Mini from the bottom put the SSD in the upper slot if you are not using another drive in the lower slot.  It is much easier to install.  You can watch the video at OWC for some hints for easy assembly.  I downloaded Trim enabler and it works great.  No fan issues on the Mini, super quiet.  You could install the original drive in the lower slot and use as a TM backup.  To install a drive in the lower slot is more involved because to really have it secure you need to pull out the main chassis of the Mini.  I have seen a drive installed without dissasembly in the lower slot using some foam tape to make it a snug fit so you would not have to dissasemble the Mini.  This may work because once the top SSD is installed the lower drive cannot really go anywhere.  I would put some foam tape between the drives to help keep the lower drive in place.

  • Hamper Level 1 (0 points)

    I'm a little confused, when you say "upper slot" you mean disassemble the whole thing to get to the HDD farthest from the opening? Installing the new SSD there and then keeping the 1TB HDD in the bay closest to the door opening for backup?


    I had some issues when using and external HDD for a Time Machine backup, because it wasn't a Time Capsule it took ages to back up and couldn't be stopped, is this the case when using the lower slot for the HDD?


    How would I install OS X then, would I keep one of the HDD bays empty, just placing the SSD in the upper most slot and installing OS X, then when having completed that, fitting in the normall HDD and OS X recognising it as another HDD, then configuring TM to use it for backup?


    I saw a video from OCW before I came here, but I wasn't sure if it would work with the M500 because of the fan/heat sensor issues with the iMac (which is what I originally wanted). Are you saying that there are still issues with the TRIM though, that Apple outright just does not support TRIM for 3rd party SSDs, that I'd need to install some extra software, is that safe?



  • tbirdvet Level 4 (2,845 points)

    When I say upper slot:  Looking at the inside of the Mini that would be the first one that you can touch right under the wireless antenna grid.  You can reach in, disconnect the cable and pull the drive out.  What I did was use carbon Copy cloner and cloned the stock hard drive to my SSD connected in an external enclosue.  Then I swapped out the drive.  You can install the original drive in the lower slot, and the then erase it and call it Time machine.  Then you could use it for that.  The trim program Apple uses only works with their SSD.  Using the free Tim Enabler program that you can download will enable trim on any non Apple SSD.  You should not have any issue using it.  It is like an app and you just turn it on or you can turn it off if needed.

  • keg55 Level 5 (7,265 points)

    Here is what I did on my Mac Mini late-2012 using iFixit's ( dual drive kit.


    I took my 500GB HDD and placed it in the supplied bracket which would be the "upper slot" (under the logic board - furthest away from bottom opening). I installed an SSD (Intel 520 120GB) in the "bottom slot" (closest to bottom opening). I did this because with Mountain Lion 10.8.3, the GUI Disk Utility will see the two drives and mark them as needing to be fixed (highlight in RED). When the FIX button is pressed, Disk Utility automatically creates a Fusion drive (logical volume group) and the 1st drive it will pickup is the one closest to the opening (bottom slot) then add in the drive furthest from the bottom opening (upper slot). This mean we want the fastest drive to be selected first (SSD) and the slowest 2nd (HDD). If the drives are in the opposite positions, then the automatic Fusion drive will be setup with the HDD then the SSD. Apple's factory implementation of the drives is as I explained intially SSD - bottom slot closest to bottom opening and HDD upper slot. I used Internet Recovery (Command+Option+R) then the GUI Disk Utility as I wanted a Fusion drive setup. I Reinstalled OS X from the OS X Utilities menu. After OS X's install and during setup, I migrated my user account/apps/data to my Fusion drive.


    If you want to use the two drives independently, you will need to use Terminal and diskutil commands to format the drives so you can use them independently. The GUI Disk Utility will ALWAYS show the two independent drives as needing to be fixed and configured into a Fusion drive.


    Terminal diskutil commands to format and label a drive.

    diskutil eraseDisk JHFS+ Primary /dev/disk1

    Where "Primary" is the label for the drive (e.g. Macintosh HD) and /dev/disk1 is the slice to format.


    Regarding TRIM, there is no need to enable TRIM in OS X for 3rd party SSDs (in my opinion). Newer drives have garbage collection and that feature handles the efficiency and performance of the SSD. My Intel 520 120GB has the SandForce controller which uses garbage collection and I don't have TRIM enabled in OS X and the drive performs great.

  • Hamper Level 1 (0 points)

    I see, I personally would describe the HDD closest to the opening the "lower" one as it was technically on the bottom of the computer, but I see what you mean. I still am not sure though if the HDD at the top then needs to be disconnected when installing OS X?


    I will probably migrate over my old files as they're on Lion and use the existing copy of Mountain Lion rather than fresh install. I will be getting a second hand Mac Mini and so will not know what I am getting until the time comes when I am ready to part with money.


    I still don't know why the Mini has two HDDs, why would Apple do that for a budget computer, after all, 1TB HDDs have been out for a while, perhaps it was to utlise that, while providing a small amount of affordable SSD for the illusion of speed?


    I think I'll start a new thread on the use of a second HDD for internal TM use, thanks for the info on TRIM, OS X really should support whatever SSD is used, I think that would be fairer to their users, but I can understand their reasons.

  • Hamper Level 1 (0 points)

    Very insightful Keg 55, thanks for that, commands included. I suppose then that the setup I want will always look bad, which will always be a featire of that computer, oh why can't my life be easy, does OS X have to behave like that. I hope I remember what will happen if I ever use Disk Utlity and get lazy!


    I remember now that I read one time TRIM can actually confuse the newer SSDs as they usually sort themselves out, I'll have to get on to the people at Crucial about that. Do I need to turn Apple's TRIM off then?



  • keg55 Level 5 (7,265 points)

    Hamper wrote:

    I hope I remember what will happen if I ever use Disk Utlity and get lazy!


    I remember now that I read one time TRIM can actually confuse the newer SSDs as they usually sort themselves out, I'll have to get on to the people at Crucial about that.

    I believe the FIX issue in the GUI Disk Utility is a 'bug' because Apple supplies an Ignore button along with the Fix button. Ignore does nothing, but put you back to the message box to Fix or Ignore. I honestly don't know what the GUI Disk Utility does after OS X is installed and independent SSD/HDD drives are used. Meaning will it show the "drives need to be fixed" error or not.


    Definitely check with Crucial. If their SSDs are using a SandForce controller and/or garbage collection, you may want to reconsider enabling TRIM in OS X using a 3rd party app like Trim Enabler. When you add your 3rd party SSD, TRIM will be disabled. So, there is no need to do anything.


    Good luck with your system. I think you'll enjoy the Mini!

  • Hamper Level 1 (0 points)

    I was just recently advised to partition the SSD smaller than the given size, this to prolong the life of the SSD:


    "rated capacity; drive manufacturers already do that in what's called "over-provisioning" and that unused space is sometimes what gets written to in the garbage collection (GC) process to support wear-leveling."







    Some information for you!

  • Hamper Level 1 (0 points)

    Crucial officially tell me that while some Mac machines may have a temperature sensor control, the Mac Mini does not have any issue with a 3rd party SSD (such as the M500 960GB) that doesn't.


    So the M500 will work fine.

  • Scubadam1 Level 1 (0 points)

    Hi Keg55 thanks for the information it worked a treat.


    The hard part seems to be getting everything up and running again.


    I booted to internet recovery and couldn't restore from timemachine without OSX existing on the drive which is now blank.


    Internet recovery will only install the OS that the machine first came with so I ended up with mountain lion. I then successfully restored my timemachine backup but my lesson's learnt is that I should have upgraded to Mavericks first as this was the OS which was installed when I took my last timemachine backup.


    I am now upgrading back to Mavericks and then will try restoring timemachine again as the system is a bit confused right now.

  • Yaptastic Level 1 (0 points)

    Thanks keg55 for describing why the SSD should be lower/bottom.  However, you referenced ifixit instructions and they show installing the SSD in the upper bay (away from the opening).  Can you clarify?

  • lllaass Level 10 (172,065 points)

    You want to install the SSD in the lower bay When you flip the Mini over to work on it it is the one on top. Some users have reported the inability to boot from an SSD in the upper bay.

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