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Compact black and silver aluminum M.2 SATA enclosure with USB-C cable

STARTECH

STARTECH SM21BMU31C3 M.2 SATA Drive Enclosure USB 3.1 Gen 2 10Gbps

SKU CH-RW9Y-EXTBF MPN SM21BMU31C3

An aluminum enclosure that turns an M.2 SATA drive into a 10Gbps USB-C portable storage device for Thunderbolt 3 hosts

  • ColorBlack / Silver
  • TypeSee Details
  • Internal InterfaceSATA I/II/III
  • External InterfaceUSB 3.1 Type-C
  • FeaturesTurn your M.2 NGFF SATA drive into an ultra-fast and portabl
  • DimensionsHeight:0.5" x Width:1.6" x Depth:3.9"

Color Black / Silver

External Interface USB 3.1 Type-C

  • Turn M.2 SATA drives into fast portable storage via USB-C
  • USB 3.1 Gen 2 delivers 10Gbps transfer speeds for large files
  • Aluminium casing draws heat away from the SSD during use
  • Works with Thunderbolt 3 ports on MacBook Pro and Dell XPS
  • Includes USB-C cable, screw kit and screwdriver for quick setup

M.2 SATA to USB-C Enclosure

The STARTECH SM21BMU31C3 converts a 2280 M.2 SATA solid-state drive into a portable USB 3.1 Gen 2 device. It targets users who want to reuse an internal SATA stick as external storage for a USB-C laptop such as a MacBook Pro or Dell XPS.

Passive Aluminium Thermal Design

The black and silver aluminium shell acts as a heatsink, so the drive runs silently with no fan and draws power solely from the host port. At .5 by 1.6 by 3.9 inches and 1.90 oz it adds negligible bulk while keeping surface temperatures low during sustained transfers.

Upgrade Path From USB 3.0 Enclosures

This unit replaces older 5 Gbps enclosures and doubles the interface ceiling to 10 Gbps, making the jump worthwhile when the source SSD can saturate SATA III. It does not support NVMe or PCIe AHCI drives, so buyers needing those protocols must choose a different model.

Highlights

  • Turn M.2 SATA drives into fast portable storage via USB-C
  • USB 3.1 Gen 2 delivers 10Gbps transfer speeds for large files
  • Aluminium casing draws heat away from the SSD during use
  • Works with Thunderbolt 3 ports on MacBook Pro and Dell XPS
  • Includes USB-C cable, screw kit and screwdriver for quick setup

Specifications

BrandStarTech.com
ModelSM21BMU31C3
ColorBlack / Silver
TypeSee Details
Internal InterfaceSATA I/II/III
External InterfaceUSB 3.1 Type-C
FeaturesTurn your M.2 NGFF SATA drive into an ultra-fast and portable storage solution for USB C enabled host including MacBook or Chromebook Pixel or Dell XPS
M.2 NGFF SATA enclosure
USB 3.1 Gen 2 (10Gbps) external enclosure with USB C
Portable M.2 SSD drive enclosure for USB Type-C enabled host
USB-C hard disk box for M.2 SATA SSDs
Compatible with Thunderbolt 3 USB C port
Aluminum M.2 SSD enclosure with ventilation
Supports SATA III (6Gbps)
DimensionsHeight:0.5" x Width:1.6" x Depth:3.9"
Weight1.90 oz
Package ContentsM.2 NGFF SATA Enclosure - USB 3.1
1 x USB C To Micro B Cable
1 x M.2 Screw Kit
1 x Screwdriver
1 x Quick Install Guide
Shipping weight0.14 kg
Package size157 × 130 × 30 mm

Other versions of this model

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Questions about this item

How do I install my M.2 SATA SSD into the SM21BMU31C3 enclosure and which step is most often missed?

Open the aluminum case, insert the M.2 SATA drive at an angle into the internal SATA connector, secure it with the supplied M.2 screw, then close the case and connect the USB-C cable; the step most often missed is using the included screw to lock the drive down, which prevents disconnects when the enclosure is moved.

What maintenance or replacement will the SM21BMU31C3 need over time?

The enclosure itself has no moving parts and requires no scheduled maintenance; only the installed M.2 SATA SSD may eventually wear out and need replacement, while the supplied USB-C to Micro-B cable can be swapped if the connector becomes loose.

What is the first performance limit I will hit when copying large files continuously through the USB 3.1 Gen 2 10Gbps port?

The internal SATA III interface caps sustained throughput at roughly 6 Gbps, so even though the external USB 3.1 Gen 2 link supports 10 Gbps, the drive’s own SATA speed becomes the bottleneck during long transfers.

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