MacMost Now 779: Apple’s New Fusion Drive

A new storage option from Apple is a compromise between a solid state drive and a hard drive. It uses both to create a single volume and automatically put the most used files in speedy SSD storage and the rest on the slower hard drive. This all goes on behind the scenes and gives nearly the speed of an SD drive at a fraction of the price.
Video Transcript / Captions
Closed captioning for this video is available on YouTube: MacMost Now 779: Apple’s New Fusion Drive.

Hi this is Gary with MacMost Now. On today's episode let's talk about Apple's new Fusion Drive.

You now have three options when buying a new Mac Mini or a new iMac. You have the standard hard drive, you have your SSD, your solid state drive, which is flash memory as a hard drive and you have something call a fusion drive which was just introduced.

So what exactly is a fusion drive and what advantage does it have over the other two.

The advantage of a standard hard drive is that it is cheap. You can get a lot of storage for a pretty low price. The disadvantage is that it is an actual disk that spins which means it's slower and it also uses more power. So using it in things like laptops will actually run the battery down a bit more.

The solid state drive, on the other hand, uses flash memory. The same things you get when get those little thumb drives that you plug into your USB port. Except that of course flash drives that are being used as hard drives are much larger, usually a 128 GB, maybe 256. There is even some that are 512 GB. Now the advantage of these is that they are much faster. There is not a moving hard disk. It is just accessing memory. So it is faster than a standard drive and also it uses a lot less power because of that. The disadvantage is price. It is much more expensive. They top out a half a terabyte and those cost about $400. So you can imagine if you want to get a one terabyte or a three terabyte SSD drive. They don't even exist but if they did it would cost a fortune to put a drive like that into your machine.

So now let's take a look at Apple's fusion drive. The Apple fusion drive is actually two drives. You've got both in your Mac. You've got a solid state drive and you have a regular hard drive. The software in your Mac, the software in Mountain Lion, is going to combine those and treat those as a single volume.

Now you may have heard of hybrid drives before. Now hybrid drives are when you have one unit that is a hard drive but also has some flash memory in it. Now when you have a drive like this basically the hard drive is your entire drive. It is all your files. The flash memory is used as a cache. So when you access a file it is also transferred to the cache for faster access next time and then it is written back to the hard drive when the drive has time to do so. Kind of like a browser cache accessing files on the internet. So it is not really increasing your space and its kind of moving files between the cache and the hard drive with the hard drive containing everything you have and the cache drive containing the files you are using at the moment or the ones that you use most frequently. So you can quickly access them.

Apple's fusion drive does not work like that. What it does is that is combines the flash memory and the hard drive to make one disk. So the files are not duplicated. They are not all on the hard drive and then cached on the flash drive. They are either on the flash side or the hard drive side, not both.

What Apple software does is to make sure that the files you access most often are on the fast flash side of the drive and the ones that you access only occasionally are on the slower hard drive.

So at the beginning say you might start off with the entire operating system and all the apps on the flash side. But then maybe as you use your Mac, maybe you install other applications, maybe you access files a lot, do a lot of different work. One person may be a video editor and another person may be editing images, another person may be doing a lot of web surfing. It is going to move files between the two drives so that the ones you access the most are on the fast side and the ones you access the least are on the slower side.

Now it is important to note that you don't need to do anything for this to happen. It all happens seamlessly in the background. You can treat it as just one hard drive that just happens to run a lot faster than a standard hard drive and almost as fast as a SSD.

Now it is very important to know that the fusion drive is a combination of hardware and software. You've got the hardware side. The flash memory and the hard disk. And you have the software side which is the way that the files are managed and that's in Mountain Lion. The latest version of Mountain Lion that will come out with these new Macs.

You can't just get a fusion drive and put it into an old Mac because it is not a single unit. It's part of the machine. In addition, you can't actually use a fusion drive with an older version of Mac OS10. You have to have the latest version because is has the software support for it. As a matter of fact you can use a Mac that has a fusion drive in target disk mode as long as the computer accessing it has the latest version of Mountain Lion to be able to handle fusion drives.

Likewise doing things that we have taken for granted before like partitioning the drive doesn't work quite the same. Apple has set it up so that you can partition the drive once and when it does it it actually creates a partition on the hard disk. So you end up with one partition of the hard disk being part of the fusion drive along with the flash memory and the second partition that you have created actually being a stand alone partition. I believe they've done this so that you can still use boot camp with boot camp being a second partition on the drive. If you are not using boot camp to run windows then you could always use disk utility. You would have to use a new version of disk utility to be able to handle the fusion drive. You can use disk utility to create the second partition but of course for most Mac users you don't need to create a second partition. That is an old way of thinking of dividing up your files. Today, especially with something like the fusion drive, it is better to just have one partition and store your files in a logical manner in folders.

So check out Apple's page with questions and answers about fusion drive. I have a feeling that more will be added to this page as more questions are asked and also as the fusion drive is deployed in actual Macs like just now in the Mac Mini. We won't have it in the new iMacs until they are released some in November and some in December.

So if you are looking for speed and quantity in a hard drive then the fusion drive on the new Mac is perfect for you. It is definitely something I will be getting on the next Mac that I buy.

I hope you found this useful. This is Gary with MacMost Now.

Comments: 7 Responses to “MacMost Now 779: Apple’s New Fusion Drive”

    6 years ago

    Hope this works better than a certain well known hybrid drive that I tried on my MBP a while ago.
    Without OS support it kept changing its mind on what was the most used and proved slower than a conventional unit

    6 years ago

    I think with the new fusion drive we will see mixed results at a premium cost. IF the only parameter OS X uses to determine what lives on the SSD is ‘access frequency’ we will have issues. I use iTunes and music on my machine constantly. I have my ripped DVD collection for streaming that gets hit all the time. This doesn’t mean I want my music or movies on expensive SSD. Personally, I would much rather have some very large video files or photos for editing (in FCP or PS) that I may reference a lot less. These would have a very noticeable load time if living on a slow 5400rpm drive. If allowed to manually chose I could simply copy those files to the SSD when ready to use them and then copy back when complete.

    While certainly better than a very slow 5400rpm spinning disk I think it will be a mixed bag – apple Apple premiums.

    Dave Estment
    6 years ago

    I have the latest Macbbok Pro 15.4 inch and have dumped the optical drive and replaced it with my original 750 HDD that came with the machine. I have replaced the HHD with a 500Gb SSD. Can I combine the two drives and make them into a fusion drive?

      6 years ago

      I’m pretty sure you can’t. You’d need the actual hardware that Apple is putting into the new machines. But with a 500GB SSD you can probably manage the files yourself (what goes on which drive) and get even better performance.

      6 years ago

      Yes . You can . Look video :

        6 years ago

        I don’t see any evidence that this method creates a fusion drive. It is just about creating a single volume from two drives, one that happens to be an SSD. That is NOT what a Fusion drive is — a Fusion drive is managing the files between the disks so the files accessed the most often are on the faster one. I don’t think that with this method that would happen at all.

    6 years ago

    I wholeheartedly agree with James. While the Fusion Drive could help out a lot of people, power users would – and should – have command over these kind of operations, i.e. enabling them to make their own choice if wanted. Too much automatics can drive some of us wild. I still remember the harrowing stories about the relentless 1-hour kick-in rule of Time Machine, which could not be changed, that could create – admittedly rarely, but just once is sometimes all it needs to rip you hair out – havoc with massive video or data operations involving swapping gigabytes of material to and fro, ending up with a stuttering Time Machine and the devout wish to have chosen another career.

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