Fusion Drive: The Future of Storage

Through the MacBook Air, Apple has pioneered the everyday use of flash storage as an alternative to traditional hard drives. With the inevitable discontinuation of the pre-2012 MacBook Pros, Apple’s MacBook lineup will go completely flash-based and it looks as if the desktop Mac is going that way to… well, kind of.

At their October special event, Phil Schiller announced Fusion Drive, a new storage technology available for configurations of Apple’s late 2012 Mac Minis and iMacs. Fusing together flash and traditional storage, Apple aims to create a faster storage medium that still offers up a large capacity. In this article, we’re going to run through the basics of Fusion Drive, the technologies behind it and what it means for the future of storage on your Mac.

What is Fusion Drive?

Essentially, a Fusion Drive from Apple has two parts: a flash storage drive and a traditional, higher-capacity hard drive. To the user, these are presented as a single logical volume with no visible distinction between what is flash storage and what is the slower, more traditional medium.

Hybrid drives are nothing new but they do differ to Apple’s Fusion Drive. Hybrid drives generally work by caching items stored on a hard drive to flash storage, mirroring them for to the quicker drive for faster access. However, Fusion Drive is different because the software dynamically moves more popular content to flash storage, leaving less frequently-access data on the hard drive.

Phil Schiller explains Apple’s Fusion Drive at their October 2012 Special Event.

Fusion Drive gives users the best of both worlds by offering faster speeds but with more overall storage. Plus, among other reasons, combining the drives rather than using the flash storage as a mere mirror offers users a combined capacity of both drivers. So, a 1TB hard drive combined with Apple’s standard 128GB of flash storage means users have a total of ~1.12TB of space to use. The 128GB flash drive can be combined with a either a 1TB or 3TB hard drive at launch.

Importantly, OS X handles everything automatically. Mountain Lion can intelligently work out which files are used more often and move them to the flash storage, relegating less-used data to the slower hard drive. Of course, the operating system is stored on the flash drive too, providing fast start up times and other advantages.

What Fusion Drive Is Not

Before Fusion Drive, there was two generally popular ways of increasing drive performance. The first is the aforementioned method of caching data from a hard drive onto a flash storage medium which is similar to Fusion Drive but means that users don’t get access to the combined capacities of both drives.

An example of a Fusion Drive setup, where the OS and frequently-used apps are located on the flash storage.

The other is RAID — redundant array of independent disks — drives, combining multiple drives into a single volume. There’s multiple methods of creating RAID drives and without writing a whole article on this technology alone, there are some minor similarities to what Fusion Drive does and performance benefits achieved with such a setup.

The Future of Storage?

In notebooks, we’re slowly getting used to using lower-capacity flash storage, with Ultrabooks and machines like the MacBook Pro with Retina Display leading the charge against slower storage. As component prices go down, so will the cost to consumers. Eventually, we may reach a time where solid state storage is affordable in capacities similar to what we enjoy with more traditional means.

Flash storage has been the medium of choice for Apple’s MacBook Airs and MacBook Pros with Retina Displays.

With a lot of consumers invested in a two-machine system (such as one laptop and one desktop), the need for higher-capacity storage on a MacBook is lower than it is on desktop. We want the speed of flash storage but the capacity of a hard drive? Fusion Drive seems like the perfect solution.

Pricing and Availability

Chances are we won’t see Fusion Drive in MacBooks, especially due to the very size constraints that played a major factor in Apple opting for flash storage versus traditional hard drives in these latest designs. However, Apple’s desktop lineup for the holidays supports Fusion Drive well with all but the ageing Mac Pro having the option to configure a Fusion Drive.

The late 2012 models of Mac Mini and iMac use hard drives as their default storage option, but Fusion Drives are configurable on all models of iMac and the 2.3GHz quad-core Mac Mini. The Mac Mini and 21.5″ iMac support a Fusion Drive with a 1TB hard drive, whereas the 27″ iMac has the option for a Fusion Drive with a 3TB hard drive too.

Fusion Drive configurations are priced slightly less than the pure SSD counterparts.

Prices for Fusion Drives on the new lineup of iMacs are unavailable as they are not yet available to order. However, supported Mac Mini can be ordered with a 1TB Fusion Drive for a $250 premium. That might seem costly, but comes in at just $50 less than the option of 256GB of pure solid state storage. Although, those wanting no more than 256GB of storage might be better suited to paying the extra $50 and going pure flash.

Final Thoughts

Fusion Drive was a surprise announcement last month, alongside Apple’s insanely thin range of new iMacs. Apple is finally attempting to move flash storage, or at least the advantages of it, to the desktop. However, like when solid state storage first came to the Mac, it’s likely Fusion Drives will continue to sell at a premium but leave a few years and it might just become the standard.

Until we get to a point where pure flash storage is an affordable possibility, Apple’s Fusion Drive signals a pleasing solution in the meantime.