I don't understand the Fusion Drive

Discussion in 'Mac mini' started by dapitts08, Apr 10, 2013.

  1. dapitts08 macrumors regular

    Jul 1, 2009
    so i just purchased a late 2012 mac mini 2.3 ghz quad core i7 with 1TB internal.

    i am adding a 250 gig samsung 840 ssd as soon as i get it.

    my plan was to run apps on the ssd (most intensive programs being the CS6 suite - fireworks, photoshop, inDesign and illustrator ... and plex for video streaming)

    i would put all of my media on the 1Tb internal.

    is there a benefit to creating a fusion drive instead?

    i have read some threads but don't really get it.

    since i would rarely be writing to the ssd.... does my original set up idea make sense?
  2. utekineir macrumors 6502

    Feb 20, 2008
    The main advantage to the fusion drive is for casual/mainstream adoption. The casual user will get the benefits of an ssd drive without having to juggle the limited space.

    What it comes down to, are you comfortable managing your files, or do you want to allow the os to handle that?

    Personally i prefer manually manage my storage. I also added an ssd internally to the mini to accompany the 1tb it came with although it was only a cheap 120gb.

    All programs and the os go on the ssd, all media stays on the platter drive. Everything is backed up to time machine in a router hard drive, a usb 3 backup, and a rotating offsite copy of that usb 3 drive.
  3. dapitts08 thread starter macrumors regular

    Jul 1, 2009
    awseome! thanks for the explanation. yeah..i would rather manage my files manually so i will stick with my original plan :)
  4. gnasher729 macrumors P6


    Nov 25, 2005
    The Fusion software lets you get the most out of your hardware.

    So your plan is: Software on the 256 GB SSD, data on the 1TB hard drive. Let's say you have 100 GB software. That means you paid for 156 GB that are of no use to you, and all your data is slow.

    First, Fusion uses _all_ of the SSD (except 4 GB write cache), so you actually use 252 GB of the 256 GB that you paid for. It puts _automatically_ all the things that are used most often onto the SSD drive. Think about it: People put OS and apps onto their SSD drive. The OS has 200 printer drivers. 198 of those are never used by you. Fusion doesn't put them onto the SSD. iTunes has support for 20 different languages. Half of the app size is for those languages. Fusion keeps the 19 languages that you don't use off the SSD drive. You start iTunes, and it displays album artwork for all your records. Guess what Fusion does: Even though that album artwork is part of the music file, only the actual album artwork gets copied to SSD and gets really fast; the rest stays on your slow hard drive. Without Fusion, either you put _all_ your music onto the SSD, which costs space, or you leave it off the SSD, so displaying the album artwork is slow.

    Why? You bought a computer to do the boring things for you. It can do that much faster and easier than you do. Managing files manually when you can avoid it is for control freaks and masochists only.
  5. utekineir, Apr 10, 2013
    Last edited: Apr 10, 2013

    utekineir macrumors 6502

    Feb 20, 2008

    when one drive ***** the bed, or when you want to reformat the os drive for a clean install.

    what then?

    Correct me if i'm wrong, but fusion in a way is sort of like a raid 0 in terms of linking 2 drives into a larger pool, just far more advanced and micro managed to leverage the advantages of the two types of drives, rather than whats basically a division of load with raid 0.

    Nothing outright wrong with that if its what you want, but it isn't all upside, you do take on a larger risk in doing so.

    Nothing wrong with being a control freak, and a drag and drop with a mouse isn't exactly the definition of machoism.
  6. paulrbeers macrumors 68040

    Dec 17, 2009
    Well what do you do right now when either of your drives ***** the bed? I don't know about you, but I keep clones of all my drives (or they are in RAID 1). So with Fusion, you have a clone of the 1.25TB "OS drive" instead of a backup of the 250GB OS drive and a backup of the 1TB Data drive. The only advantage of having them separated in your scenario is that you are only recovering 1 drive instead of 2 and if it is your data drive that goes out you can still use the OS.

    In any case though, if you have a drive failure, you should replace it as soon as possible anyway just in case my backup drive fails as well!
  7. utekineir macrumors 6502

    Feb 20, 2008
    Still, can we agree linking drives introduces a greater risk, and there are advantages to maintaining distinct volumes for different purposes, rather than a conglomerated hodgepodge.

    The last i was reading fusion was nice and all and fantastic in the mainstream market it is intended for, but gave no real tangible advantage for someone who doesn't have a mental hurdle when it comes to working with more than one hard drive.

    Not saying there aren't upsides to fusion, just the upsides have a distinct diminishing returns the more comfortable you are with managing a computer.
  8. dapitts08 thread starter macrumors regular

    Jul 1, 2009
    i would rather not unecessarily write to the ssd....why would i add that wear and tear to the ssd just to use the additional storage....i get that from my external...i didn't buy the ssd to increase my storage...that is what the 1TB internal and any externals i add are for...
  9. paulrbeers macrumors 68040

    Dec 17, 2009
    Even early on, it was proven that this isn't even a concern. Here's an article from anandtech from 2008 that stated that even if you wrote 100GB of data to your SSD, that after 5 years your data is still completely intact (I'd be happy with even a mechanical drive lasting 5 years).


    In fact I think I read something like, an average user would get something like 37 years before the flash memory begins to wear out with "normal" SSD's.
  10. dapitts08 thread starter macrumors regular

    Jul 1, 2009
    do you have an article like that which specifically addresses the samsung 840 series (non-pro) 250 gig? if so, I would be interested in seeing what the life span is for the specific drive I have over a generalization. for instance, from what i have read the life cycle for the samsung pro is longer than the regular series.
  11. utekineir macrumors 6502

    Feb 20, 2008
    regarding fusion as a whole

    there are a bunch of links at the end of this article from other sources,

    in particular


    which subjectively suits my argument.

    per the anand tech link withink the barefeats article

    suck it long, suck it hard trebek
  12. dapitts08 thread starter macrumors regular

    Jul 1, 2009
  13. FreakinEurekan macrumors 68040


    Sep 8, 2011
    Eureka Springs, Arkansas
    I don't agree. If all your apps are on one drive and all your data is on the other, the loss of either drive puts you out of business until you replace it & restore the data. Same thing happens if one drive goes in a Fusion. The only difference is you're restoring the full volume, instead of just your app or your data volume.

    Now if you're going to keep your data on a RAID-1 external or NAS and you want just your boot & apps on SSD with NO internal data storage, then your risk is reduced. But if you're not mirroring either volume, and both volumes are critical, then the risk of Fusion vs. distinct volumes is basically the same (and the performance is worse, and there is wasted space on the SSD).
  14. paulrbeers macrumors 68040

    Dec 17, 2009
    Here's a review I recommend you read on Fusion. Anand is a Mac user, but is more than willing to call out Apple when he sees a failure on their part.



    I'd say I'm more than comfortable with managing a computer, but to be honest anymore I'd rather take a back seat and let the managing be done for me. That's half the reason I switched to Apple products. I got tired of having to "manage" my Windows machines. Life is too short to care about what drive I am writing to. I still technically have my Mini split as two drives, but that's going to change the next time I have some time off.

    And while I agree, there is an advantage that if it is JUST your data drive that goes down, you can at least still use your Mac, again I contend that if any drive of mine goes down I am replacing it ASAP just in case I lose my backup drive as well (and be completely out of luck).

    How long would you wait to replace your data drive should it fail?
  15. niteflyr macrumors 6502a

    Nov 29, 2011
    Southern Cal
    I gotta agree with Freakin here. I went with the separate drive setup and now wish I gone the fusion route. I'll probably fuse it some rainy weekend when I have nothing else to do.
  16. utekineir macrumors 6502

    Feb 20, 2008
    Would not skip a beat.

    There would be no real interruption if it were the data drive.

    Basically would just pull data from the usb volume instead of the internal.
  17. paulrbeers macrumors 68040

    Dec 17, 2009
    But at some point in time, you are going to replace said internal right? And then copy your data back to the internal right?!?! that's an interuption. how long would you truly wait to do this? Knowing that you no longer have a backup right? Because your backup is now your production drive. This is why if ANY of my hard drives go down I go get a replacement ASAP. Do you not do this? Do you really take the chance that your backup drive (that is now your prod data drive) doesn't fail leaving you without any backup?!?!
  18. utekineir macrumors 6502

    Feb 20, 2008

    Good article, but the end result is still the same as had been stated.


    My work needs consist of expense tracking, document and picture record keeping and tax prep.

    Not exactly high end.


    Getting back to workflow interruption.

    Fusion : either drive goes down the array as a whole would need to be rebuilt right?

    Separate: restore os drive image, or media volume folders to an external and keep on chugging.

    Was running the ssd boot drive on my mini for a couple months as usb 3 till i got around to ordering the extra drive internal kit. Just was using an intel sata/usb adaptor from a retail box kit, actually worked much better than I had expected.
  19. leman macrumors G3

    Oct 14, 2008
    Fusion is clearly a greater risk. Still, it does not matter, as you are supposed to have the backups in any case. Full data failure is as bad as only partial data failure.

    As to the second part (there are advantages to distinct volumes): yes, but only for special workflows. For instance, if you are a video professional who works with large videos, setting up a separate disk only for videos will increase both the performance and the reliability. However, this issue is orthogonal to the Fusion drive. The Fusion drive is designed as the 'default' drive, where you have your applications and data. For large videos and other specialised work you should use external drives in any case (does not matter if you have Fusion or a normal drive). That is what you have that fancy Thunderbolt/USB3 for.


    There is no practical difference. The solution in both cases is exactly the same and takes the same amount of time:

    1) replace the faulty drive
    2) restore from backup
  20. paulrbeers macrumors 68040

    Dec 17, 2009
    So if an internal drive fails. You switch to your backup. And you will never replace your internal drive.

    Basically, you are skirting the question. Regardless if your needs are "high end" or not, you will end up replacing the internal drive and copying everything back to that drive. You don't want to agree with this, because it proves what we have said that regardless of EITHER drive failing, you will replace those and that will cause an interruption to your work flow just like if a drive failed in Fusion would interupt your work flow. Guess what, I can always switch to my USB backup drive too if I needed to continue to use my computers RIGHT now as well, but that's not a risk I'm willing to take. Lose everything and run the risk of losing all of my family pictures, all of my work over the last few years, etc? Lunacy.

    Further, if your needs aren't high end, why would getting the absolute fastest speed out of your system even matter then? My needs ARE high end running multiple VM's, storing massive databases, etc and even I'm willing to take a chance on the Fusion drive because I'd rather not have to worry about where all of my files are and whether my more regularly accessed VM's are on the SSD or my less used databases are on the data drive. Let OSX handle that.
  21. utekineir, Apr 10, 2013
    Last edited: Apr 10, 2013

    utekineir macrumors 6502

    Feb 20, 2008

    2tb Time machine

    4tb drive of copied folders, images and instal files dating back the last number of computers

    4tb ccc copy intended for offsite safekeeping.

    Theres also a floater 1.5tb usb 3 from a costco deal that keeps a copy of the media and aperture libraries. Also should be a few old 500gb-1tb usb 2 externals around.

    Not really worried.


    You're being really nitpickingly anal.

    of course it would get replaced when i get around to it, but as stated there are enough extra drives that i wouldn't feel rushed.

    I'm an impatient person and have spent the last 20 years actively dabbling with computers. Think i can be entitled to reasonably fast drives if i want. Few hundred dollars in drives is still on a low budget compared to real storage arrays.

    Would you like to rip me for buying an rmbp with no real professional need too? Because you can do that.
  22. paulrbeers macrumors 68040

    Dec 17, 2009
    Would you just admit, that at some point you are going to replace the dead drive and copy everything back just like I would do if one of the drives failed with fusion setup?

    Again, you know we are right, at this point you just don't want to admit that we have a point. You continue to skirt the question.


    No. I'm making a point. Regularless if your drives are separate or one unified drive (like Fusion), you are going to replace the drive and copy everything over.

    That's whether the drives are separate or combined. So your point about how Fusion is a bigger risk is laughable because as you have pointed out: You have still have a backup and now you finally agree that you will replace the drive and you will copy everything over. In the end there is little benefit.

    You can always boot OSX up via USB so even if the fusion drive goes, you can always boot to your backup via USB or Thunderbolt or Firewire or whatever and continue to use your computer (albeit somewhat slower).
  23. utekineir macrumors 6502

    Feb 20, 2008

    My point, as it has been from the start.

    a) by all accounts its a great implementation for the mainstream market, but doesn't necessarily offer any significant advantage for the person ok with managing a computer. i.e. different strokes for different folks

    b) with fusion if one drive goes down both the os and storage volume are affected, without fusion they are fully independent.

    That can lead to a greatly reduced interruption in workflow depending on the backup methods utilized by the individual. Really the degree of interruption depends on the individual situation.

    c) when can we meet in the back room of a microcenter for potbellied monkey sex? Do you like balding, slightly overweight 30 year olds? I'm tall but kinda hung like a 3 year old.
  24. dapitts08 thread starter macrumors regular

    Jul 1, 2009
    i have no idea how we got here ... lol

    but thanks to everyone who provided input

    i feel that i am making an informed decision now
  25. opinio macrumors 65816

    Mar 23, 2013
    Not sure if this has been mentioned in the thread, but my understanding is that because you have a 2012 Mac Mini, your only choice will be the fusion setup when you have a SSD and HDD internally. That is, disk utility forces you to 'fix' it (from my experience) to make it a fusion drive.

    I saw a post somewhere I think from philipma about how to set up an unfused setup of a SSD and HDD in the current Mac Mini if you want to take that path.

    If you choose to fuse the drives then there should be no issue, but if you want a traditional separated setup then you might want to confirm my point with some of the experts.

    Sorry if this has been mentioned already.

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