OWC
OWC Express 1M2 4TB USB4 40Gb/s Portable NVMe SSD Storage Solution
Bottom line: The OWC Express 1M2 4TB USB4 40Gb/s Portable NVMe SSD Storage Solution: Up to 3836MB/s real-world reads, over 2x typical Thunderbolt portable enclosures; main trade-off: full 40Gb/s speeds need a USB4 or Thunderbolt host, not plain USB-C.
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Pros & Cons
Pros
- ✓ Up to 3836MB/s real-world reads, over 2x typical Thunderbolt portable enclosures
- ✓ Solid aluminum shell doubles as a fanless heatsink for sustained write speed
- ✓ Accepts your own M.2 2280, 2242, or 2230 NVMe drive
- ✓ Works with USB4, Thunderbolt, and USB-C hosts without adapters
- ✓ 3-year OWC warranty on the full solution, 2 years enclosure-only
Cons
- ✗ Full 40Gb/s speeds need a USB4 or Thunderbolt host, not plain USB-C
- ✗ 4TB configuration sits at a premium over sealed portable SSDs
- ✗ DIY bay means opening the case and seating the drive yourself
- ✗ Aluminum body runs warm to the touch during sustained transfers
Manufacturer description
The OWC Express 1M2 is a 4TB USB4 portable NVMe SSD enclosure solution built around a solid aluminum shell that doubles as a heatsink. OWC rates it at up to 3151MB/s, with real-world figures cited up to 3836MB/s over a 40Gb/s link -- roughly twice what most Thunderbolt 3 portable enclosures deliver. It connects to USB4, Thunderbolt, and USB-C hosts, so the same drive moves between a MacBook Pro, a Thunderbolt-equipped PC, and a plain USB-C tablet without adapters. What separates this OWC portable SSD from sealed rivals is the DIY bay: the enclosure accepts M.2 2280, 2242, or 2230 NVMe…
SpecPicks Verdict
SpecPicks scored OWC Express 1M2 4TB USB4 40Gb/s Portable NVMe SSD Storage Solution using a rating × review-volume × price-fit model applied to published specs and reviews across the external storage category. OWC's external storage lineup sits within the broader category mid-tier; price and specs are the deciding factors over brand loyalty here. Judge it on the specification table and the price rather than on sentiment: check the figures that decide your use case, then put it side-by-side with two or three close alternatives in the Compare tool before clicking through.
Common buyer scenarios for external storage of this kind: matching it to an existing build, replacing a failing part, or upgrading from a previous-generation equivalent. Check the spec table below against your current setup — particularly socket / form-factor / power-rating fields — and confirm compatibility on the retailer's listing before purchase. Prices and stock are set by the retailer and may have moved since this page was last updated.
Frequently Asked Questions
How fast is the OWC Express 1M2 4TB in real use?
OWC rates it up to 3151MB/s, and cites real-world performance up to 3836MB/s on a 40Gb/s USB4 connection -- over twice what typical Thunderbolt portable enclosures reach.
Will it work with my MacBook or a regular USB-C laptop?
Yes. It is compatible with USB4, Thunderbolt, and USB-C computers and devices. Slower USB-C ports will connect but cap throughput below the 40Gb/s ceiling.
Can I install my own NVMe SSD instead of the 4TB drive?
Yes. The enclosure takes your choice of M.2 2280, 2242, or 2230 NVMe SSD, and OWC includes the screwdriver needed to open it.
Does it need a power adapter?
No. It is bus-powered and palm-sized, drawing what it needs from the host port, so the included 40Gb/s USB-C cable is the only connection required.
What warranty does OWC provide?
OWC lists a 2-year Limited Warranty on the enclosure and 3 years on the complete solution. Check the product listing for current terms in your region.
Key Features
- Ultra-fast: over 2x faster than Thunderbolt portable enclosures with up to 3836MB/s real-world performance
- Ultra-compatible: use with USB4, Thunderbolt, and USB-C computers and devices
- Ultra-reliable & Innovative: Patented heat-dissipating design offers rugged protection of your SSD while silently keeping drive cool for consistent top speed
- Flexible DIY: use your choice of NVMe M.2 2280, 2242, or 2230 SSD
- Portable: bus-powered and palm-sized for convenient use anywhere
- Complete: includes 40Gb/s USB-C cable and screwdriver for enclosure
Full Specifications
| Brand | OWC |
|---|---|
| Color | Silver |
| Complete | includes 40Gb/s USB-C cable and screwdriver for enclosure |
| Portable | bus-powered and palm-sized for convenient use anywhere |
| Model Name | Express 1M2 |
| Read Speed | 3151 Megabytes Per Second |
| Ultra-fast | over 2x faster than Thunderbolt portable enclosures with up to 3836MB/s real-world performance |
| Unit Count | 1.0 Count |
| Worry-free | 2 Year (enclosure) or 3 Year (solution) OWC Limited Warranty |
| Form Factor | portable |
| Media Speed | 3151 Megabytes Per Second |
| Connectivity | USB-C |
| Flexible DIY | use your choice of NVMe M.2 2280, 2242, or 2230 SSD |
| Model Number | OWCUS4EXP1MT01 |
| Built-In Media | 40Gb/s USB-C cable, Assembly Manual and User Guide, OWC Express 1M2, Screwdriver (enclosures only) |
| Hard-Drive Size | 4 TB |
| Mfr Part Number | OWCUS4EXP1MT04 |
| Number of Items | 1 |
| Special Feature | Portable |
| Ultra-compatible | use with USB4, Thunderbolt, and USB-C computers and devices |
| Full listing title | OWC Express 1M2 4TB USB4 40Gb/s Portable NVMe SSD Storage Solution | Up To 3151MB/s - Bus-Powered - USB4/Thunderbolt/USB-C Compatible - Solid Aluminum Protects/Cools |
Ready to buy?
OWC Express 1M2 4TB USB4 40Gb/s Portable NVMe SSD Storage Solution | Up To 3151MB/s - Bus-Powered - USB4/Thunderbolt/USB-C Compatible - Solid Aluminum Protects/Cools is listed on Amazon. Price, availability, shipping and returns are set by Amazon and its sellers — check the listing for current terms. SpecPicks earns a small commission on qualifying purchases — thank you for supporting independent review work.
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