OWC miniStack STX

This clever storage and expansion solution is intended as the perfect companion to a Mac Mini.

Other World Computing computer peripherals are targeted at people working in the media industries, and although nearly all of their products are cross‑platform, many are optimised to meet the needs of Apple users. None more so than the miniStack STX! As the name and form factor suggest, it’s designed to sit neatly below or above a Mac Mini, and the expansion options it offers particularly complement that model.

U OK Hub?

When connected using the supplied cable to a Thunderbolt 4 PC or an Apple computer running Mac OS 11.1 or later, the miniStack serves as a Thunderbolt 4 hub, adding three Type C Thunderbolt ports to whatever complement the host machine has, and supplying up to 60W of power for laptops. Unlike OWC’s Thunderbolt Dock, though, the miniStack doesn’t duplicate other Mac Mini expansion ports such as USB Type A, Ethernet and the headphone jack. Most people probably don’t need more of these, so this seems sensible, but it’s a shame there’s no SD card reader. Since Thunderbolt 4 is a ‘container’ for USB, you can also connect the miniStack using a USB cable to Macs running legacy versions of Mac OS, non‑Thunderbolt Windows machines and even iPads, Chromebooks and Android devices, in which case it will operate as a USB hub.

What the miniStack does have that the Thunderbolt Dock doesn’t is the ability to host non‑removable media, courtesy of both a SATA port that can accept either a 2.5‑ or 3.5‑inch drive, and a connector for an NVMe M.2 solid‑state drive. These can be used simultaneously, so you could for example use a fast NVMe drive for sample library or project storage and a slower SATA drive for backup, or you could set up a RAID system. However, the NVMe storage is accessible only over Thunderbolt; computers connected using USB will see only the SATA drive.

The miniStack is available either ‘bare’ or pre‑populated in various configurations. The review unit shipped with an OWC‑branded 2TB NVMe drive, but installing your own is extremely simple: four bolts on the base of the unit need to be removed, whereupon the lid can be lifted off and your drive fitted. There’s plenty of space and none of the usual obstructions you’ll encounter when trying to fit a drive into a typical PC tower or rack case.

Stacking Up

In the flesh, the miniStack follows the contours of the Mac Mini with pleasing accuracy, though its mirror‑like upper surface and darker case make clear that it’s not one. A four‑pin socket next to the Thunderbolt connectors accepts 20V DC from the line‑lump power supply. The OWC logo lights up when the miniStack is powered, and there are also separate activity LEDs for the SATA and NVMe drives. Once a connection to the host computer is established, the miniStack also spins up its built‑in fan. This seems to operate continuously and is clearly audible, though not obnoxiously loud. I would be surprised if a fan is always necessary in configurations that don’t have a SATA hard drive, so it’s a pity this can’t be disabled.

What the miniStack does have that the Thunderbolt Dock doesn’t is the ability to host non‑removable media.

I tested the miniStack with a new MacBook Pro running Mac OS 12.2.1 ‘Monterey’. With the supplied NVMe drive, Blackmagic Design’s Disk Speed Test reported write and read speeds of around 700 and 800 MB/s respectively. This is fast enough for all conceivable audio applications and most video uses, but around half of what I measured with the simpler Envoy Express a few months back. Using a Thunderbolt 3 instead of a Thunderbolt 4 cable reduced these figures slightly, but not by much.

As long as you’re in a position to connect it via Thunderbolt, then, I think the miniStack STX is a neat solution to most of the expansion problems that confront Mac Mini users — and many others besides. It’s every bit as useful with Apple laptops, and I’m sure there are many Windows machines that will likewise benefit from its combination of Thunderbolt expansion and additional storage.