Sonnet's Fusion Flex J3i Mount Lets You Add Up to Three Internal Drives to Your Mac Pro

Sonnet today announced the upcoming launch of its Fusion Flex J3i internal drive mount for the 2019 Mac Pro, which lets users add up to three SATA storage drives to their machines.

sonnet fusion flex installed
Sonnet isn't the only company to launch an internal drive mount for the new ‌Mac Pro‌, and Apple itself sells Promise's Pegasus J2i system that lets you add two drives, but Sonnet says it's the first to let users add three drives right inside the ‌Mac Pro‌ and connected directly via SATA.


The Fusion Flex J3i offers two slots that can accept either 3.5-inch hard disk drives or 2.5-inch SSDs, and a third slot that accepts a 2.5-inch SSD, allowing for a total of 36TB of additional internal storage.

Storage installed via the Fusion Flex J3i won't be as fast as the main NVMe SSDs at the heart of the ‌Mac Pro‌ or PCIe-based storage upgrades, especially if you're using traditional hard disk drives, but if you're a user who wants to prioritize storage space and simplicity over drive speed, Sonnet's Fusion Flex J3i might be worth checking out.

sonnet fusion flex kit
The Fusion Flex J3i includes the mount, required power/data cable assemblies, and mounting brackets to fit 2.5-inch drives into the 3.5-inch drive slots, but the drives themselves are sold separately. It will be priced at $199.99 and launches on June 15.

Related Roundup: Mac Pro
Tag: Sonnet
Buyer's Guide: Mac Pro (Neutral)
Related Forum: Mac Pro

Top Rated Comments

Rychiar Avatar
51 months ago
wait these things don't allow more than one in the first place??
Score: 8 Votes (Like | Disagree)
WildCowboy Avatar
51 months ago

wait these things don't allow more than one in the first place??
The stock storage is either one or two Apple-proprietary storage modules tied to the machine's T2 chip. You can go up to 8TB total with those.

Beyond that, it's either PCIe-based storage, internal SATA like this, or external options.
Score: 8 Votes (Like | Disagree)
Darth Tulhu Avatar
51 months ago
There was a time when I would drool over stuff like this (I still kinda do).

My days of popping the hood are behind me (even though I've been keeping my 2011 17", and 2012 iMac and 15" alive for the last couple of years with those skills).

I'm amazed that we live in an age where I can ACTUALLY replace my hardware with an iPad!

I no longer need the power this machine offers, even if I think it's cool that it can provide it.
Score: 8 Votes (Like | Disagree)
Stang Avatar
51 months ago
$200 for a piece of plastic and 3 sata cables? Yikes.
Score: 8 Votes (Like | Disagree)
SSDGUY Avatar
51 months ago

wait these things don't allow more than one in the first place??
I believe they can take two drives without an expansion mod.
Score: 5 Votes (Like | Disagree)
theluggage Avatar
51 months ago
$200 for a mounting bracket and 2 slightly-customised SATA cables that should have been included with the Mac in the first place...

To be fair, the third cable is a USB3-to-SATA cable which might set you back as much as $7!

Sheesh. I've bought entire PC cases that cost less than $200 and they don't charge extra for the flippin' drive brackets. ...and that's premium Fractal Design/Silverstone stuff that you can compare with Apple and keep a straight face, although the Mac Pro blows right past "premium" and into "over-engineered to the point of parody"...

OK, I know all the big IT firms will charge you $50 for a cable tie if they think you're ordering with a corporate credit card and not watching the price, but that doesn't make it right - and they're usually doing it to compensate for under-bidding on support contracts.


Super weird how the third caddy connects via and internal USB3 cable, rather than SATA like the other two.
...probably because there are only 2 SATA connectors (plus a USB-3) on the Mac Pro mainboard...?
Score: 5 Votes (Like | Disagree)

Popular Stories

iOS 18 Siri Integrated Feature

iOS 18 Will Add These New Features to Your iPhone

Friday April 12, 2024 11:11 am PDT by
iOS 18 is expected to be the "biggest" update in the iPhone's history. Below, we recap rumored features and changes for the iPhone. iOS 18 is rumored to include new generative AI features for Siri and many apps, and Apple plans to add RCS support to the Messages app for an improved texting experience between iPhones and Android devices. The update is also expected to introduce a more...
Delta Feature

Delta Game Emulator Now Available From App Store on iPhone

Wednesday April 17, 2024 9:58 am PDT by
Game emulator apps have come and gone since Apple announced App Store support for them on April 5, but now popular game emulator Delta from developer Riley Testut is available for download. Testut is known as the developer behind GBA4iOS, an open-source emulator that was available for a brief time more than a decade ago. GBA4iOS led to Delta, an emulator that has been available outside of...
iOS NES Emulator Bimmy Feature

NES Emulator for iPhone and iPad Now Available on App Store [Removed]

Tuesday April 16, 2024 11:33 am PDT by
The first approved Nintendo Entertainment System (NES) emulator for the iPhone and iPad was made available on the App Store today following Apple's rule change. The emulator is called Bimmy, and it was developed by Tom Salvo. On the App Store, Bimmy is described as a tool for testing and playing public domain/"homebrew" games created for the NES, but the app allows you to load ROMs for any...
iGBA Feature

Apple Removes Game Boy Emulator iGBA From App Store Due to Spam and Copyright Violations

Sunday April 14, 2024 9:22 pm PDT by
Apple today said it removed Game Boy emulator iGBA from the App Store for violating the company's App Review Guidelines related to spam (section 4.3) and copyright (section 5.2), but it did not provide any specific details. iGBA was a copycat version of developer Riley Testut's open-source GBA4iOS app. The emulator rose to the top of the App Store charts following its release this weekend,...
iPhone 15 Pro Action Button Translate

All iPhone 16 Models to Feature Action Button, But Usefulness Debated

Tuesday April 16, 2024 6:54 am PDT by
Last September, Apple's iPhone 15 Pro models debuted with a new customizable Action button, offering faster access to a handful of functions, as well as the ability to assign Shortcuts. Apple is poised to include the feature on all upcoming iPhone 16 models, so we asked iPhone 15 Pro users what their experience has been with the additional button so far. The Action button replaces the switch ...
iGBA Feature

Game Boy Emulator for iPhone Now Available in App Store Following Rule Change [Removed]

Sunday April 14, 2024 8:06 am PDT by
A week after Apple updated its App Review Guidelines to permit retro game console emulators, a Game Boy emulator for the iPhone called iGBA has appeared in the App Store worldwide. The emulator is already one of the top free apps on the App Store charts. It was not entirely clear if Apple would allow emulators to work with all and any games, but iGBA is able to load any Game Boy ROMs that...