OWC’s Mac mini-size Thunderbolt hub also adds terabytes of storage [Review]


OWC MiniStack STX★★★★★
The OWC MiniStack STX is designed to stack with a Mac mini and add ports and storage capacity.
Photo: OWC

The OWC MiniStack STX is just the right size to stack with a Mac mini. The hub adds three Thunderbolt 4/USB-C ports that can be hooked to high-resolution displays and external drives.

It also includes bays for SATA and/or NVMe M.2 drives. That’s space for up to 18TB of storage. Install your own drives or buy them from OWC.

I put the powerful accessory for Mac or iPad to the test over several weeks of daily use.

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OWC MiniStack STX review

Despite its diminutive size and relatively low price, the Mac mini is quite a powerful desktop. Especially the version with an Apple M1 processor. The computer is intended for consumers, but many people use it for professional tasks.

That often requires terabytes of storage. The Mac mini can be configured with up to 2TB, but with the OWC MiniStack STX the total can grow to many more terabytes.

And while the Mac mini has a pair of Thunderbolt 3 ports, OWC’s peripheral adds more. It acts a Thunderbolt hub, and each of its three downstream ports offers high-speed connections to whatever accessories you need.

As part of my testing, I made it the hub of my home office. It was connected to my iPad Pro and a USB-C monitor, plus other accessories from time to time.

Which brings up an important point: while MiniStack STX is sized to stack with a Mac mini, it is certainly not limited to that device. It’s fully compatible with any recent Mac or iPad Pro.

Hub/drive enclosure designed for Mac mini stacking

OWC MiniStack STX review
The MiniStack STX fits a lot of capabilities into a neat package.
Photo: Ed Hardy/Cult of Mac

At first glance, the OWC MiniStack STX looks like a black Mac mini. That’s intentional, of course, for ideal stacking.

The hub/drive enclosure is 7.8 inches square and 1.5 inches thick. The corners are rounded to match Apple’s desktop.

The OWC logo on the front lights up white when the peripheral is getting power, and blue when connected to a computer. A pair of green LEDs also on the front light up to show drive activity.

A DC power cable plugs into the back. This accessory needs a sizable power supply – it’s close to half the size of the main unit. Not that this really matters because you’ll hide it under your desk.

Add a trio of Thunderbolt 4 ports

OWC MiniStack STX Thunderbolt 4 ports
Four Thunderbolt/USB-C ports: three “downstream” ports and a single “upstream” port. (Those are cooling vents to the right.)

The OWC MiniStack STX’s four ports are all on the back. One of these is the “upstream” port used to connect to your computer that can handle up to 60 wats of power. The other three are for accessories. They all support Thunderbolt 4 and offer data transfers at up to 40 Gbps (5,000 MBps).

As real-world speed testing for the ports, I brought in an OWC Envoy Pro SX, an external SSD that supports Thunderbolt. I copied a 10.5 GB file from my computer to the SSD in 9 seconds while using the MiniStack as a hub. I copied the same file from the external drive to my computer in 27 seconds.

I also did an accidental test. When reviewing the Samsung USB Type-C Flash Drive, I mistakenly did some of the speed tests with the drive plugged into the MiniStack STX. Naturally, I had to do the tests again with the tiny drive plugged directly into my computer, but the speed results were essentially the same. I certainly didn’t notice a difference until I saw the tiny drive was in the wrong spot.

The exact data transfer speeds you get will depend on the computer you connect OWC’s hub/drive enclosure with.

While the MiniStack STX’s ports offer Thunderbolt 4, they are backward compatible with earlier standards. You can plug USB-C accessories in, and even USB-A ones with an inexpensive adapter.

I should point out that while doing all these speed tests, OWC’s hub is also handling my Innocn 27-inch 4K Computer Monitor running at 60 Hz. There’s plenty of bandwidth here.

All the ports face backward. If you want front-facing ones, you need to add another hub. Fortunately, Thunderbolt accessories can be daisychained.

Also a SATA and NVMe drive enclosure

More than just a Thunderbolt hub, the OWC MiniStack STX is also a drive enclosure. Inside are a SATA HDD/SSD bay and an NVMe M.2 PCIe SSD slot.

The hub is available without any drives, or you can buy it preconfigured with up to 18 TB of storage. My review unit came with a 2TB, 3.5-inch SATA hard drive from Western Digital, model WD20EZBX.

Open the OWC MiniStack STX to reveal the drive bays.
Open the OWC MiniStack STX to reveal the drive bay and slot.
Photo: Ed Hardy/Cult of Mac

To test its speed, I copied the same 10.5 GB file used earlier from my computer to the HHD, which took 46 seconds. I copied the same file from this drive to my computer in 52 seconds. An HHD naturally has slower read/write speeds than the SSD I tested earlier.

Opening the OWC MiniStack STX to insert or take out a drive is as easy as removing a few of screws. Slot the drive into place, close up, and you’re done. It couldn’t be easier.

OWC MiniStack STX final thoughts

A tidy desk is a happy desk. At least that’s what my kindergarten teacher told me – my desk often looks like a bomb went off on it. But the MiniStack STX offers Mac mini users a combination Thunderbolt hub and drive enclosure that stacks nearly with their desktop, and also cuts down on cord clutter.

It’s a very useful combination of additional Thunderbolt/USB-C ports and room for additional storage.



The OWC MiniStack STX starts at $279 for the version without preinstalled drives. The price goes up from there to $1,249 for an 18 TB version.

Buy from: OWC

Buy from: Amazon

If you have more space on your desk and a need for even greater storage capacity, consider the OWC Mercury Pro U.2 Dual instead. It goes up to 64 TB. I reviewed that massive drive enclosure as well.

OWC provided Cult of Mac with a review unit for this article. See our reviews policy, and check out more in-depth reviews of Apple-related items.


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