Final Words

For the first time since late 2008, I went back to using a machine where a hard drive was a part of my primary storage - and I didn’t hate it. Apple’s Fusion Drive is probably the best hybrid SSD/HDD solution I’ve ever used, and it didn’t take rocket science to get here. All it took was combining a good SSD controller (Samsung’s PM830), with a large amount of NAND (128GB) and some very aggressive/intelligent software (Apple’s Core Storage LVM). Fusion Drive may not be fundamentally new, but it’s certainly the right way to do hybrid storage if you’re going to do it.

It seems that Fusion Drive is really made for the user who doesn't necessarily have a ton of applications/data, but does have a reasonable sized media collection. For that user, Fusion Drive should be a reasonable approximation of a well managed SSD/HDD setup with your big media files going to the HDD and everything that you launch frequently living on the SSD. I’m always going to ask for a larger cache, but I do believe that 128GB is a good size for most client workloads and usage models today. For me in particular I’d probably need a 256GB cache for Fusion Drive to win me over, but I understand that I’m not necessarily the target market here.

The real question is whether or not it’s worth it. I’m personally a much bigger fan of going all solid state and manually segmenting your large media files onto HDD arrays, but perhaps that’s me being set in my ways (or just me being right, not sure which one). Fusion Drive doesn’t do anything to mitigate the likelihood that a hard drive will likely fail sooner than a good SSD, whereas if you go with an internal SSD and external (Thunderbolt or USB 3.0) HDD RAID array you can control your destiny a bit better. Unfortunately, in situations where Fusion Drive is a choice, you don’t often have that flexibility.

On the iMac, Apple limits your options quite a bit. You can either buy a hard drive or the Fusion Drive on the 21.5-inch model, there’s no standalone SSD option. There the choice is a no-brainer. If you’re not going to buy your own SSD and replace the internal HDD with it (or try to see if OWC’s rMBP SSD fits), then the Fusion Drive is absolutely right choice. You’re paying handsomely for the right ($250 for 128GB of NAND is very 2011), but if you’re not willing to crack open the iMac case this is really the only way to go.

For the 27-inch iMac the decision is similarly difficult. Apple does offer a standalone SSD option, but it’s for a 768GB model that will set you back $1300. All of the sudden that $250 Fusion Drive upgrade sounds a lot more reasonable.

On the Mac mini side the decision is far simpler. The Fusion Drive is only available on the $799 configuration (for $250) but so is a 256GB SSD upgrade for $300. As long as you’re ok with using an external hard drive for mass storage, here I’d go for the big standalone SSD. The usual caveat applies: this  is only true if you’re not interested in cracking open the mini yourself and using a 3rd party SSD.

To make things simpler, I made bold the options I'd choose given Apple's current lineup in the table below. Note that this is still assuming you're not going down the DIY route (if you do go down that path, buy the biggest SSD you can find and rely on some external mass storage for everything else):

Fusion Drive Options
  Mac mini (2012) 21.5-inch iMac (2012) 27-inch iMac (2012)
Base System Cost $799 $1299/$1499 $1799/$1999
1TB Fusion Drive +$250 +$250 +$250
3TB Fusion Drive - - +$400
Largest Standalone SSD 256GB
(+$300)
- 768GB
(+$1300)

I am curious to see how long of a roadmap Fusion Drive has ahead of it. Will NAND get cheap/large enough that even the iMac can move to it exclusively? Or will we end up with systems that have more than enough NAND to easily store everything but large media files for even the most demanding of power users? In less than a year Apple could double the size of the NAND used in Fusion Drive at no real change to cost. I suspect another doubling beyond that would be necessary to really make Fusion Drive a one size fits all, but then we're talking ~2 years out at this point and I don't know how static everyone's usage models will remain over that period of time. Go out even further in time, to the post-NAND era and there are some really revolutionary things that can happen to the memory hierarchy altogether...

Fusion Drive Performance & Practical Limits
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  • tipoo - Friday, January 18, 2013 - link

    Feeling self-important today? Yes, that's what I mean, there hasn't been a doubling since the fourth generation Nano. Or does "Been a long time since a capacity doubling from them" mean "they have never ever doubled capacity" in your little world? Reply
  • tipoo - Friday, January 18, 2013 - link

    "Then there is a year or two of stasis, then a new product category which requires more storage."

    Like the iPads, which would be ideal for storing HD video if not for the exorbitant prices of higher capacities, with zero bump for the base price since the first one?
    Reply
  • tipoo - Friday, January 18, 2013 - link

    To your last point Name99, indeed they will. Reply
  • name99 - Friday, January 18, 2013 - link

    As compared to all those other tablets out there with 128 and 256GB of storage? Like uuh, huh, wait, the names will come to me...

    When EVERYONE is doing things a certain way, not just Apple, it may be worth asking if there are other issues going on here (limited manufacturing capacity and exploding demand, for one) rather than immediately assuming Apple is out to screw you.
    Reply
  • Death666Angel - Friday, January 18, 2013 - link

    Tons of Archos stuff, Samsung XE700, Gigabyte and Dell tablets etc. have >120GB storage. Reply
  • name99 - Friday, January 18, 2013 - link

    So in other words the tablets that are trying to be laptop replacements, and that have to cope with the massive footprint of Windows 8.

    You may consider this to be proof against my point; I don't.
    Reply
  • Hrel - Friday, January 18, 2013 - link

    "You can create Boot Camp or other additional partitions on a Fusion Drive, however these partitions will reside on the HDD portion exclusively."

    So you CAN create a Boot Camp partition on a Fusion Drive, it just won't utilize the SSD portion of that fusion drive at all. Or am I not understanding you?
    Reply
  • Hrel - Friday, January 18, 2013 - link

    *facepalm, I read "you can't create..." nm me... whistle whistle whistle Reply
  • Shadowmaster625 - Friday, January 18, 2013 - link

    May as well take that $400 to downtown detroit...

    Seriously though why in blazes are HDD manufacturers having such a hard time with this. How hard is it just to throw 4GB of SLC onto the little circuit board of a 1TB HDD? Yes, all you need is 4GB. The controller simply needs to perform a very simple algorithm... If the file you are writing is greater than 4MB in size, write directly to the HDD. It is a large sequential write and thus HDD performance will be adequate. If its a small write (< 4MB), write that to the SLC cache. That one tiny little optimization will get you 90% of the performance of a Vertex 4. (Depending on the bandwidth of this 4GB of SLC of course). But really it doesnt need to be as fast as a vertex 4. It just needs to be in that ballpark, for small random I/O. Large sequential I/O can just skip the NAND altogether.
    Reply
  • Ben90 - Friday, January 18, 2013 - link

    Lol, stupid. System32 and SysWOW64 would fill your NAND on installation. Reply

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