iMac 1TB Fusion... OS on SSD part?

Discussion in 'iMac' started by kirkbross, Jan 13, 2016.

  1. kirkbross macrumors 6502a

    kirkbross

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    #1
    In the 1TB Fusion drive associated with the cheapest new iMac, is the OS on the SSD portion of the drive?

    i.e. is it worth $100 just to have a snappier OS?
     
  2. dimme macrumors 65816

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    #2
    I have a sad in my rMBP and a fusion in my iMac. The OS seems just as snappy on both. The software in OS X does a pretty good job of moving the most used files to the SSD. For my iMac I opted for the fusion because I needed the space.
     
  3. ApfelKuchen macrumors 68020

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    #3
    The point of Fusion is not to just have a snappier OS - the entire computer will be snappier. OS, data, apps... all can be resident on that SSD.

    That's the difference between Fusion (an automated process that optimizes the use of an expensive resource) and simply putting your OS and apps onto a separate SSD because you believe OS and apps benefit most from being on SSD (while data is not that important). If you do data-intensive work, your data deserves to be on SSD, too.

    I have two Late 2013 iMacs. One has pure SSD, the other has Fusion. As a practical matter, it's hard to tell the difference between the two - they're both far faster than any HDD-only machine I've used.

    Fusion doesn't put the entire anything on the SSD - it makes its decision based on data blocks, not folders or files. If a data block is in use (a block may contain multiple files, or a fraction of a single file), it's going to SSD. If it remains in fairly regular use, it stays there. If it hasn't been used for some time, it may go back to HDD in favor of something that's in current use. If it's never used, it stays on HDD.

    Due to the nature of an OS (frequent use of a core group of functions), a fair chunk of it is likely to stay permanently on the SSD. There are parts that may never make it to the SSD, because they're never used. Why allocate 25% of that 24 GB SSD permanently to the OS if, say, 50% of the 6 GB OS is never used?
     
  4. maflynn Moderator

    maflynn

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    #4
    The issue though, is unlike prior Fusion drives, the 1TB fusion drive has a tiny 24GB flash drive and as such, its hard to put the OS and anything else on it.

    Personally, the major reason why I went for the 2TB Fusion drive is that it has the 128GB flash storage.
     
  5. ApfelKuchen macrumors 68020

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    #5
    I have no doubt that 128 GB will have benefits for people who work with large data files and pro apps (considering I've seen some professional scenarios where 256 GB might be more suitable). I'm far from convinced that 24 GB is necessarily a problem for the typical purchaser of a base-level iMac (even the base-level Retinas), who's mostly browsing the web, checking email, watching streaming videos on YouTube, and working on fairly small documents. I have little doubt that, for the purchasers of near-base iMacs, 24 GB is more than enough to boot the system and commonly-used consumer apps at pure SSD speeds - and boot is generally when the speed of SSD is most obvious to the layperson.

    Here's what Apple has to say about it in the product configurator > "How much storage is right for you?"(emphasis added):
    Let's put this in perspective - 128 GB is the entire capacity of a base MBA. Just what percentage of that is likely to be actively utilized by the typical user of that model?

    I can appreciate the widespread, "WTF, only 24 GB" response, but it's not based on benchmarking results - it's a purely gut-level assessment. I prefer to think that Apple has a solid, statistical basis for what it's doing. Every person with a 128 GB Fusion who agreed to share usage data with Apple has contributed to Apple's working knowledge of just how that SSD is utilized. If Apple learned that it can reduce the size of the cache by 80% and still deliver $100 worth of performance boost, super. Apple's more profitable, and customers are still happy. (If I had to make a prediction, we'll be seeing 24 GB Fusion as standard equipment by Late 2016.)
     
  6. robgendreau macrumors 68030

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    #6
    I sorta agree with you both; one doesn't know what the OP uses day to day, and the OP might benefit from the larger one. Or not. But I'd still vote 2TB Fusion just because 1TB is just really small these days. Sure, you can expand with externals, but it seems like a poor economic decision to go just 1TB on such a machine. That is, unless you were say supplying a classroom of 'em where they were pumping away 24/7 just running Word for writing classes or whatnot. And that applies to the whole cheapo 21.5" iMac altogether; it just isn't a very good value all around IMHO.
     
  7. bogg macrumors 6502

    bogg

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    #7
    I have an early-2013 13" Retina MBP with 256GB of SSD, I have used it quite extensively for web browsing, movie watching and e-mail since I got it as well as for some word and excel work for my job. Without any major cleanup done in the 2.5 years I've had it, it still has 145GB of free space. 128GB SSD is enough for most ordinary users. On my iMac though, I filled and cleaned out my 1TB drive a few times before I even had owned it a year. Completely depends on how you use your machine. For most ordinary users 24GB is more than enough to speed up most everyday tasks.
     
  8. tdhurst macrumors 68040

    tdhurst

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    #8
    Hell yes it's worth $100 to have a snappier OS.
     
  9. maflynn Moderator

    maflynn

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    #9
    I'll grant you that my complaints against the 1TB Fusion drive is not based on benchmarks but it is based on what I do, how I use the Mac and what files I have, and I'm pretty certain that I use a number of files and apps that would exceed that flash amount, heck, when you factor in the OS, there's a lot less in the 24GB available for you. Also while I don't have benchmarks, I have played with them in the apple store and while not scientifically accurate, I did find the Macs with the 1TB drives to feel slower then the higher spec'd macs on the display floor.

    Overall, its just my twisted logic that 128GB of storage will be able to hold more of my files, so accessing those files will be much faster then on a hard drive. Another benefit, is the 2TB Fusion drive (at least on the 5k) uses a 7200rpm drive, which is another advantage.
     
  10. tdhurst macrumors 68040

    tdhurst

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    #10
    So your complaints are based on playing with a Mac on a showrooms floor, and real experience from others and benchmarks doesn't override that?
     
  11. T'hain Esh Kelch macrumors 601

    T'hain Esh Kelch

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    #11
    Dont buy the 1TB drive as mentioned above, get the 2TB version. And yes, totally worth it.
     
  12. Fishrrman macrumors G3

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    Feb 20, 2009
    #12
    OP asks:
    "i.e. is it worth $100 just to have a snappier OS?"

    YES, of course it is.
    That $100 represents only a small portion of the buy-in price.

    BTW:
    You SHOULD NOT consider the 1tb fusion model, because the SSD portion is a measely 24gb.
    You SHOULD get the 2tb fusion model instead, because its SSD portion is 120gb.

    That's enough to hold the OS, apps, and reasonably-sized user folders.
     
  13. kirkbross thread starter macrumors 6502a

    kirkbross

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    #13
    OP here... my second question was unnecessary — I absolutely know it's worth $100 (even more, imo) to have a snappier OS on an SSD. My first question was really the only relevant question.

    Is the SSD part of a fusion drive a physically separate drive with its own partition or is it some kind of Frankenstein construction?
     
  14. AppleNewton macrumors 68000

    AppleNewton

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    #14
    There are two separate SATA drives that are installed. "Fusion" is a form of core storage that basically tells the system firmware there are two physical drives acting as one, and the software/OS recognizes that to do its data organization.
     
  15. blut haus macrumors regular

    blut haus

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    #15
    I have a mid level iMac 5K (3.2GHz i5) with the 1TB fusion drive and 16GB of RAM. I opted for the slightly better GPU. I use Photoshop to edit rather large RAW images, and final cut pro X to edit 1080 footage. I'm not hurting for speed anywhere on this machine. I didn't think it was worth the extra cash to get a pure SSD setup or a larger fusion drive. People seem to be freaking out a bit about the smaller flash storage, but as I said, definitely not hurting for speed here. I understand everyone has their own usage scenarios. I use two Pro apps, but I'm by no means a Pro as in I don't make money from this stuff, its just a hobby. Maybe if you were a Pro making cash it would be different, but then you'd probably be using the Mac Pro...just my thoughts.

    I found it a better value to put the extra money into RAM (third party) versus a larger drive. Maybe I'll regret it down the line, but at this point I'm not going to trade this machine back in. I'm just going to roll with it. What a first world problem to call a HDD in a brand new machine "slow". Yep, that extra 2 seconds I have to wait for it to boot up sure inconveniences me /sarc

    And no, I'm not saying SSD's aren't "fast". Of course they are. I just don't care about that little bit of extra speed in my case.
     
  16. ZipZap macrumors 601

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    Dec 14, 2007
    #16
    So the current fusion drives do not have 128GB SSD anymore?

    I have the previous gen iMac 5K, I was thinking about splitting the fusion drive. 128GB could hold the oS and more. 16 or 24GB is useless.
     
  17. Stang68 macrumors 6502a

    Stang68

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    USA
    #17
    I just ordered the same config as you but on the 21.5" iMac. Glad to hear performance is snappy since I'll be using the same pro apps as you!
     
  18. blut haus macrumors regular

    blut haus

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    #18
    The 21 inch has integrated graphics, though, yeah?
     
  19. bogg macrumors 6502

    bogg

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    #19
    2TB has 128GB, 1TB is 24GB SSD
     
  20. Erdbeertorte macrumors demi-goddess

    Erdbeertorte

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    #20
    Here are my speed tests again if anyone is interested.


    120GB SDD from split up Fusion Drive:

    [​IMG]

    2TB HDD from split up Fusion Drive:

    [​IMG]


    And the 1TB SSD (I think the 512 and 256GB have the same speed, only the smaller ones from the fusion drives have a much slower write speed):

    [​IMG]
     
  21. maflynn Moderator

    maflynn

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    #21
    The 1TB has 24GB, and a 5400 rpm drive, the 2TB has 128GB of flash storage and uses a 7200rpm drive. I think that combination gives you the best balance of speed and cost imo
     
  22. bent christian, Jan 15, 2016
    Last edited: Jan 15, 2016

    bent christian Suspended

    bent christian

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    #22
    I am pretty sure this is not correct.

    Everything I have seen leads me to believe that the 21.5" iMac has a 5400rpm drive in any configuration. Any Fusion configuration.

    The 27" has a 7200rpm drive in any configuration.

    Looking inside the of 21.5" iMac, it becomes obvious that there is no room for a 3.5" drive. Everything is packed in very tight. This is why Apple has used 5400rmp drives since the remodel in 2012. It is a space issue. Making room for that one drive would require a redesign of the entire inside layout. This is obviously not something Apple would do for only two models. We all know the business model and how the company operates.

    We can also look at Apple's habit of using modular parts a given model size. They want everything to be interchangeable, particularly at the low-end.
     
  23. bogg macrumors 6502

    bogg

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    #23
    Yes, from my understanding 21.5" = 5400 2.5", 27" = 7200 RPM 3.5"
     
  24. blut haus macrumors regular

    blut haus

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    #24
    Yes, the 27 inch has a 7200 RPM drive.
     
  25. ZipZap macrumors 601

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    Dec 14, 2007
    #25
    Current and previous generation iMac 27 5k's?

    --- Post Merged, Jan 15, 2016 ---
    This would indicate that the 2TB drive without the SSD performs poorly? Very Poorly.

     

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