Which M.2 SSD Fits a Thunderbolt NVMe Enclosure?

An external Thunderbolt SSD is only as good as the drive inside it. Pick the wrong one and it won't be recognized at all, or it'll run well below what the enclosure can do. This is what to check before you buy a drive for a Thunderbolt NVMe enclosure like our SSD Enclosure 1.

What 2230, 2242, 2260 and 2280 mean

M.2 is a form factor, and the four-digit code is the drive's size in millimeters. The first two digits are the width and the last two are the length, so a 2280 drive is 22 mm wide and 80 mm long.

2280 is the common size for desktop and laptop SSDs, and it has the widest choice of capacities. 2230 is the short drive found in some compact laptops and handheld gaming PCs. 2242 and 2260 are less common lengths that show up in some laptops and industrial machines. SSD Enclosure 1 takes all four.

NVMe, not SATA

M.2 describes the shape of the drive, not how it talks to the computer. An M.2 drive can be NVMe, which runs over PCIe, or SATA, which is older and slower. A Thunderbolt NVMe enclosure carries PCIe, so it needs an NVMe drive. SSD Enclosure 1 works with NVMe drives keyed M or M and B. M.2 SATA drives, often labeled SATA or NGFF, won't work, even though they look almost identical.

Capacity

SSD Enclosure 1 supports drives up to 8TB. The SSD isn't included, so you can buy the capacity you need or reuse a drive you already have.

What speed to expect

The 40Gbps on the box is the Thunderbolt link rate. Real transfers are lower, because the PCIe data inside a Thunderbolt link is capped below 40Gbps and every protocol adds overhead. Thunderbolt NVMe enclosures typically land around 2,500 to 3,000 MB/s, depending on the drive and the computer. In our own test on a MacBook Pro, SSD Enclosure 1 read at about 3,170 MB/s and wrote at about 2,930 MB/s.

A PCIe 3.0 NVMe drive is enough to fill that bandwidth. PCIe 4.0 and 5.0 drives work too, since they're backward compatible, but the extra speed won't show up over Thunderbolt. If you move big files, look at a drive's sustained write speed, not just the headline number on the box.

Heat

NVMe drives slow themselves down when they get hot. SSD Enclosure 1 has an on-demand fan, and the box includes thermal pads for the drive, to help keep long transfers from throttling.

Check your computer's port

You need a Thunderbolt 3 or Thunderbolt 4 port to get Thunderbolt speeds. Most Macs from recent years have one. On a Windows PC, look for the lightning-bolt icon next to the USB-C port, or check the spec sheet. A plain USB-C port is not the same thing.

Before you buy

• M.2 NVMe (PCIe) drive, M key or M and B key
• Length 2230, 2242, 2260 or 2280
• Up to 8TB
• A Thunderbolt 3 or 4 port on your computer
• Formatted for how you'll use it: APFS for Mac only, exFAT to share between Mac and Windows

Picked your drive? SSD Enclosure 1 ships from Ontario, Canada.