Apple's New 'Fusion Drive' Not a Typical Hybrid Drive

Amongst the many new products Apple introduced today, they also announced a new storage option called Fusion Drive. Apple's website describes how the drive works:

With Fusion Drive in your iMac, disk-intensive tasks — from booting up to launching apps to importing photos — are faster and more efficient. That’s because frequently used items are kept at the ready on speedy flash storage, while infrequently accessed items go to the hard drive. The file transfers take place in the background, so you won’t even notice.

NewImage30

Some thought the drive might be Apple's implementation of a Hybrid drive which uses SSD as a caching system, but it appears that Apple's system is distinct. The MacObserver digs into some details and clarifies:

To be clear, this is not a caching concept, at least not in the current use of the word. Cache would imply that the data on the SSD is duplicated, and it's not. If you have a 1TB mechanical drive paired with the 128GB SSD, you have a 1.12 TB storage platform. This truly is the fusion of all the space on two separate disks.

Ars Technica compares it to an enterprise feature called Automated Tiered Storage.

In a caching solution, like Intel's, files live on the hard disk drive and are temporarily mirrored to the SSD cache as needed. In an enterprise auto-tiering situation, and with Fusion Drive, the data is actually moved from one tier to another, rather than only being temporarily cached there.

The Mac Observer reports that there are two separate drives that appear as one logical partition. As a result, if your Hard Drive fails, it could be replaced with a 3rd party drive and reconfigured as a Fusion Drive.

Meanwhile, they note that all writes take place on the SSD drive, and are later moved to the mechanical drive if needed, resulting in faster initial writes. The Fusion will be available for the new iMac and new Mac mini models announced today.

Related Roundups: iMac, Mac mini
Related Forums: iMac, Mac mini

Popular Stories

iphone 16 display

iPhone 17's Scratch Resistant Anti-Reflective Display Coating Canceled

Monday April 28, 2025 12:48 pm PDT by
Apple may have canceled the super scratch resistant anti-reflective display coating that it planned to use for the iPhone 17 Pro models, according to a source with reliable information that spoke to MacRumors. Last spring, Weibo leaker Instant Digital suggested Apple was working on a new anti-reflective display layer that was more scratch resistant than the Ceramic Shield. We haven't heard...
iPhone 17 Air Pastel Feature

iPhone 17 Reaches Key Milestone Ahead of Mass Production

Monday April 28, 2025 8:44 am PDT by
Apple has completed Engineering Validation Testing (EVT) for at least one iPhone 17 model, according to a paywalled preview of an upcoming DigiTimes report. iPhone 17 Air mockup based on rumored design The EVT stage involves Apple testing iPhone 17 prototypes to ensure the hardware works as expected. There are still DVT (Design Validation Test) and PVT (Production Validation Test) stages to...
Beyond iPhone 13 Better Blue

20th Anniversary iPhone Likely to Be Made in China Due to 'Extraordinarily Complex' Design

Monday April 28, 2025 4:29 am PDT by
Apple will likely manufacture its 20th anniversary iPhone models in China, despite broader efforts to shift production to India, according to Bloomberg's Mark Gurman. In 2027, Apple is planning a "major shake-up" for the iPhone lineup to mark two decades since the original model launched. Gurman's previous reporting indicates the company will introduce a foldable iPhone alongside a "bold"...
apple watch ultra yellow

What's Next for the Apple Watch Ultra 3 and Apple Watch SE 3

Friday April 25, 2025 2:44 pm PDT by
This week marks the 10th anniversary of the Apple Watch, which launched on April 24, 2015. Yesterday, we recapped features rumored for the Apple Watch Series 11, but since 2015, the Apple Watch has also branched out into the Apple Watch Ultra and the Apple Watch SE, so we thought we'd take a look at what's next for those product lines, too. 2025 Apple Watch Ultra 3 Apple didn't update the...
iphone 17 air iphone 16 pro

iPhone 17 Air USB-C Port May Have This Unusual Design Quirk

Wednesday April 30, 2025 3:59 am PDT by
Apple is preparing to launch a dramatically thinner iPhone this September, and if recent leaks are anything to go by, the so-called iPhone 17 Air could boast one of the most radical design shifts in recent years. iPhone 17 Air dummy model alongside iPhone 16 Pro (credit: AppleTrack) At just 5.5mm thick (excluding a slightly raised camera bump), the 6.6-inch iPhone 17 Air is expected to become ...
iPhone 17 Pro Blue Feature Tighter Crop

iPhone 17 Pro Launching Later This Year With These 13 New Features

Wednesday April 23, 2025 8:31 am PDT by
While the iPhone 17 Pro and iPhone 17 Pro Max are not expected to launch until September, there are already plenty of rumors about the devices. Below, we recap key changes rumored for the iPhone 17 Pro models as of April 2025: Aluminum frame: iPhone 17 Pro models are rumored to have an aluminum frame, whereas the iPhone 15 Pro and iPhone 16 Pro models have a titanium frame, and the iPhone ...
iPhone 17 Pro on Desk Feature

All iPhone 17 Models Again Rumored to Feature 12GB of RAM

Tuesday April 29, 2025 3:36 am PDT by
All upcoming iPhone 17 models will come equipped with 12GB of RAM to support Apple Intelligence, according to the Weibo-based leaker Digital Chat Station. The claim from the Chinese leaker, who has sources within Apple's supply chain, comes a few days after industry analyst Ming-Chi Kuo said that the iPhone 17 Air, iPhone 17 Pro, and iPhone 17 Pro Max will all be equipped with 12GB of RAM. ...
AirPods Pro 3 Mock Feature

AirPods Pro 3 Just Months Away – Here's What We Know

Tuesday April 29, 2025 1:30 am PDT by
Despite being more than two years old, Apple's AirPods Pro 2 still dominate the premium wireless‑earbud space, thanks to a potent mix of top‑tier audio, class‑leading noise cancellation, and Apple's habit of delivering major new features through software updates. With AirPods Pro 3 widely expected to arrive in 2025, prospective buyers now face a familiar dilemma: snap up the proven...

Top Rated Comments

Stetrain Avatar
163 months ago
This is actually not needed if apple went with 256GB as standard :rolleyes:

How would having a 256GB SSD replacing having a 1TB or 3TB hard drive?
Score: 36 Votes (Like | Disagree)
JesterJJZ Avatar
163 months ago
Personally, an SSD boot drive and separate large HD seems more practical. No need to "fuse" them into one volume. Just seems like asking for trouble.
Score: 32 Votes (Like | Disagree)
gregwyattjr Avatar
163 months ago
This feature is perfect during this HD to SDD transitional period. It'll keep things affordable while still supplying great performance.
Score: 30 Votes (Like | Disagree)
arn Avatar
163 months ago
and most likely that's exactly what it is. It has been available on PCs for a while.
read the article again. seems different

arn
Score: 21 Votes (Like | Disagree)
Stetrain Avatar
163 months ago
Personally, an SSD boot drive and separate large HD seems more practical. No need to "fuse" them into one volume. Just seems like asking for trouble.

The fusion drive is just software to automatically handle that. Most consumers probably don't want to have to deal with having a boot drive and a data drive. Some things can be tricky to get onto an external drive, like iTunes and iPhoto libraries.
Score: 19 Votes (Like | Disagree)
makingdots Avatar
163 months ago
Very interesting, though I'm wondering what if one of those drives fail. Is your data retrievable from the other one?
Doesn't matter. We have Time Machine. :D
Score: 14 Votes (Like | Disagree)