Other World Computing (OWC) has launched a new line of NVMe SSD upgrades for several Mac models that used Apple's custom not-quite-M.2 form factor. The new Aura Pro X2 is OWC's third generation aftermarket storage upgrade for Apple's custom SSD form factor.

Apple was an early adopter of PCIe SSDs in the consumer space, introducing them to several models in 2013. In recent years they have phased out the use of replaceable SSDs in favor of using their own SSD controller built in to the T2 security chip, but there is still a large install base of pre-TouchBar MacBook Pros and non-Retina MacBook Airs that can accept storage upgrades. Aftermarket upgrade options for these machines were initially very limited until macOS 10.13 added NVMe support, which allowed off the shelf M.2 NVMe drives to be used with a passive adapter—however, those adapters are a bit too thick for Apple's notebooks (they fit just fine in the cylinder Mac Pro).

Before macOS supported NVMe, OWC provided the Aura SSD, which was essentially two SATA SSDs in RAID-0 behind a Marvell controller that only supported a PCIe 2.0 x2 host interface. The Aura's performance was poor, but it did offer the option of upgrading storage capacity, which was particularly useful for the MacBook Air models that never offered a factory 1TB SSD option. The Aura was followed up by the Aura Pro X based on the Silicon Motion SM2260 controller, which meant OWC was still struggling to offer better performance than the Samsung and SanDisk drives Apple shipped. The new Aura Pro X2 uses the Silicon Motion SM2262EN and offers performance and power efficiency on par with current high-end SSDs in standard M.2 form factors, and includes the first 2TB SSD in Apple's form factor.

OWC sells the Aura Pro X2 as either a standalone drive or in an upgrade kit that includes their Envoy Pro USB enclosure for the stock SSDs the Aura Pro X2 replaces, and the necessary pentalobe and Torx screwdrivers to perform the upgrade. The upgrade kit is $70-80 more expensive than the bare drive.

Prices for the Aura Pro X2 are quite steep compared to retail M.2 NVMe SSDs—they're more like what the MLC-based Samsung 970 PRO sells for, rather than in line with other TLC-based NVMe SSDs.

We have a review sample of the 960GB Aura Pro X2 on hand. It has already completed most of our usual consumer SSD test suite and those results are available in our Bench database, but for the full review we'll also be doing some macOS testing.