Express 1M2 40Gb/s Portable NVMe SSD USB4 (Thunderbolt Compatible/USB-C) Ultra Fast External SSD Drive with Aluminum Heat Sink Enclosure (Enclosure Only)

I've been very impressed with the OWC Express 1M2 (40Gb/s). I was able to very easily install my own SSD and extend the storage space for a new Apple Mac mini while saving several hundred dollars. The OWC Express 1M2 along with the SSD now hold my Apple Home folder and everything is external to the Mac mini. I've got a thunderbolt 4 Mac mini. I opted to go with the 40Gb/s OWC Express 1M2 because thunderbolt 5 speeds in the 80Gb/sec version would have no meaningful impact except for "future proofing". The drive and SSD speeds are great. I've never experienced any transfer speed issues. I've only noticed that the drive/SSD get ejected about every 3 weeks. I'm not sure the cause but am in contact with OWC to find a solution. Other than that, it works perfectly. My OWC express 1M2 is connected and on 24x7. It has a solid build and is always cool to the touch. I would recommend turning the light brightness down when installing any SSD. It's not overly bright but I do see the activity light flashing during the night if I'm awake.

I've bought a few different external drive systems over my lifetime, but none as quality on par as this chonky boy. It is thicc, you may notice the same thing, but I'll tell you why it's for good reason. I purchased the 0TB version of the OWC Express 1M2 SSD enclosure and I paired this up with a Samsung 990 Evo Plus. My needs for more hard drive space was quickly realized when the base Mac mini M4's measly 256 GB of storage wasn't gonna cut it. #basemodelgang The premium quality straight out of the box was noticeable in my hands. Heavy. It feels well made and the aluminum reminds me of an expensive tool. It looks cool, I think. Matches the color of my Mac enough. All the fins, slices, across the top of the enclosure allow a massive amount of heat to be dispersed passively. No fans, no noise. And it works well! I have noticed it gets warm to the touch, but nowhere near concerning. It supports PCIe 4.0. It's not the most portable SSD, I will say that is a downside, but it can be for the occasional need. I like that it's thin enough to slide into the front pouch of a backpack. The better part of this setback, is that it allows me to edit videos in Final Cut Pro directly from the drive right as it sits on my desk. Quietly operating, without a sound. It's fast, faster than anything I've used and almost double to internal Mac mini read/write speeds and averages above 3,000 for both. I think this product is for someone who wants to expand their computer with more storage, but doesn't mainly travel with it. If your priority is portability, you may already know this isn't for you. The things that make it not so great option to carry, are the exact reasons you want it when performance and sound are what you are looking for in your search for an external hard drive.

I am using this with a 2021 M1-Max Macbook Pro, paired with the Playstation Drive, the Western Digital Black SN850X 8TB ! IMPORTANT NOTE! I had to return the SN850X with heatsink, as you must get the naked version for use with this drive! Due to true Thunderbolt 4 support, this is the fastest external drive I've ever had with my Mac, sustaining 3 GB/sec read+write! Before this, the best I achieved was 1TB/second using those USB 3.2 drives. And unlike with a lot of ready made external drives, this one was easily formatted and partitioned in Disk Utility, with no special hoops to jump through. It's worth addressing that the size issue is absolutely not bad at all. Yes, this is about twice the size of a compact external SSD, but for true perspective, it is smaller than my iPhone 16 Pro, and because it's a sturdy aluminum case, you can stash it as is in your backpack. I use this drive for very large backups, and during my initial backup of a 3.8TB folder, which took over a half hour due to having over 5 million files, the case definitely got hot. Not serious burn hot, but "I don't really want to hold this in my hand" hot. I do not consider this an issue, as future backups will be deltas, and what you get is pure silence. ( There aren't many high performance 8TB drives on the market, but I trust the SN850 to be reliable, due to its extensive track record with the Playstation 5, and it was the second cheapest 8TB SSD I found ). All in all, I think OWC really knocked it out of the park with this external drive! For a single external SSD, this is a no brainer as the best possible choice! :)

I don’t usually leave reviews, but this one absolutely earned it. I’m running a 2024 Mac mini (M4) with a 4TB Crucial P3 PCIe Gen3 NVMe SSD. Previously I had it in a UGREEN 10Gbps enclosure, and it was a constant headache—random disconnects (especially overnight) and inconsistent speeds. I picked this up mainly to fix that issue, not expecting a huge performance jump—but it delivered both. Setup was extremely simple. It comes with a screwdriver, and you just remove two exterior screws to open the enclosure and one internal screw to secure the SSD. Took just a few minutes. Build quality feels solid and the aluminum design helps with heat—warm at most, never hot. I already had my SSD (picked it up on Black Friday), but it’s nice they offer models that include SSDs as well if you need a complete solution. After installing, I ran multiple tests using Blackmagic Disk Speed Test (both 1GB and 5GB stress tests) and saw a huge improvement: • ~2400–4000 MB/s write • ~2800–3000 MB/s read Compared to my previous setup (~900 MB/s write / ~500 MB/s read), this is a massive difference. File transfers are noticeably faster, apps load quicker, and overall responsiveness is much better. Compatibility has been excellent so far on macOS 26.3.1 with zero issues. Most importantly—no disconnects. If you’re on a newer Mac (especially Apple Silicon like the M4) and dealing with slow speeds or unreliable enclosures, this is a serious upgrade. Completely changed my setup. it’s small, sleek aluminum design to help dissipate heat. Nice Mac like design. Comes with cable, screwdriver and extra bottom pads.

Size - 4TB. Even though it says 4TB, the actual capacity that I see in the drive is 3.84TB and available space is 3.6TB which is strange. I'll need to contact the vendor to understand why the entire 4TB is not available. I formatted this drive on my Mac before using (APFS Encrypted) but still see 3.84TB available. Not sure why. Compatibility - I only have Apple devices so can only talk about Macs. I connected it with a thunderbolt 4 cable to my thunderbolt 4 port on my Mac Studio. The speed is incredible. No issues. It was basically a plug and play device with advertised speeds. I see a 2581 for read data but write is 3141 MB/S. Transferring 108GB from my iCloud account took a min so very happy about that. Drive Quality - It feels very sturdy and quality product. The size is small and something you can easily travel with. Not heavy. I feel that if the internals work as advertised then this should last me for several years. Overall I'm very pleased with the quality, speed and functionality of the drive. Everything looks good except the fact that the drive is 3.84 TB and not 4TB as advertised. I'll provide an update after contacting the vendor. Oct 2, 2025 - UPDATE: I spoke with AWC support desk and the response that I received was that the reason that I see 3.6TB available space is because of over provisioning. This means that a portion of the SSD's total storage is set aside by the drive to optimize performance and to extend life span. All this is good but it is almost 400GB of space for optimization. That's a lot. Here's what the Readme.txt file from AWC says and I quote "Setting up your new drive takes just a few minutes and is as simple as launching the included utility and following the on-screen instructions. When finished, your new drive will have its full capacity and be completely optimized for use with your computer system." I didn't use the utility and instead formatted the drive. From what I'm told, it wouldn't have made a difference. Losing this much space is a bummer but other than that this drive is truly amazing speed and quality wise. I still love the performance and functionality. Support response was pretty quick and professional. Hoping that this drive lasts me a few years.

Really high quality housing. From OWC I would expect no less. I bought this enclosure to use mostly with my music library, as the hard drive I had been storing my (many) MP3s on was starting to click, and I was afraid it would fail. I purchased this enclosure for a Crucial P310 1TB SSD, PCIe Gen4 NVMe M.2 2280 so my music library could be safe into the future. It works seamlessly with my Macbook Air M3. After playing music for a while, the enclosure does get warm to the touch (as it should - that means it's transferring heat from the SSD to the air) but never hot. The drive responds immediately, unlike the hard drive I was using previously. There is no lag at all with this SSD and enclosure, it responds super fast. My one issue is that it is bus-powered, and my laptop battery drains faster when using this enclosure and SSD. So I just keep an eye on the battery level or I keep my laptop plugged in when using this.

I have three of these OWC 1M2 enclosures and they are designed well and work well. They keep the installed WD SN850X NVME SSD passively cooled to within a temp range of 40-50 deg C. No fan means no noise and inherently more reliable. Read/write speeds are as expected and I am very happy with the overall simplicity, reliability and performance of this enclosure. Because it cools passively, it needs the large fins and this makes it larger than other fan cooled models, so I use these for my desktop computers where they operate 24/7. When traveling, I use a fan cooled enclosure which is smaller and more portable. Some people have noted disconnect issues when used on a Mac Studio with multiple displays and other peripherals attached, and I have encountered the same. I ran tests and adding a powered hub to my Mac Studio completely resolved this problem. The Studio seems to have issues powering multiple peripherals from its own ports. I’ve recently had two power outages at my home, and both times my Studio (running on a CyberPower UPS) powered back up and all the peripherals and this enclosure reconnected successfully. I will buy more when needed.

If you’re like me and edit photos and videos for a living while also not wanting to overspend on Apple’s higher storage tiers, this is a godsend! My previous enclosure for a 4TB SSD was an ORICO 40Gbps model with a fan. It was among the first of the 40gbp models at the time, but problems began immediately when using it on my Mac. It would disconnect multiple times, only stopping after I manually ejected and reconnected the drive. This put my video and image files at serious risk as anyone in our line of work would know, but I brushed it off as a design quirk until I discovered the real issue. Overheating. The ORICO would get so hot that it could literally burn you if you touched the metal top of its plastic shell. My breaking point came when, in the middle of an edit in Final Cut Pro, the drive disconnected yet again. That was when I decided to cut my losses, wrap it up, and search for the fastest, most reliable solution i can find. I'm happy to say that search ended with this OWC enclosure and honestly, I couldn’t be happier. Not only does it do exactly what it’s supposed to, but I can finally work without worrying about disconnects or losing my files. The solid metal body and finned design act as a massive heatsink, pulling heat away from the SSD and dissipating it naturally. This keeps the drive safe from overheating, prevents thermal throttling, and ensures I can take FULL advantage of my SSD’s maximum performance. Also while yes it goes get warm, you won't have to worry about burning yourself like the old drive I had. All this mind you, is working without a fan! That's how good the heat management on this thing is! Design-wise its's perfectly matched to my M4 Pro Mac Mini setup, it's small, and lightweight. You don't need extra software or drivers that are needed to run it, you just plug it in and it shows up as a storage device on Mac. The only setup required on your end is applying the thermal tape so it makes solid contact with both the SSD chips and the enclosure. It's nice and thick so you know its going to make full contact on both parts. This is my first OWC product, and it certainly now won’t be my last. If I could give it 10 stars, I would!!!

Whilst expensive, it absolutely delivers. I have a good consistent speed with no speed throttling due to thermal constraints. Everything else is as it states in the spec I used this on a M4 mini and can confirm 3200 as quoted.

This OWC Express 1M2 is a fantastic enclosure. It's incredibly small and portable, making it easy to toss into a backpack pocket. Paired with the Samsung 990 Pro 4TB SSD, the performance is flawless. I've been editing 4K video in Final Cut Pro on my M1 Max Mac Studio in real-time, and I've experienced zero slowdowns—a huge step up from my previous drives. While it does get noticeably warm under heavy load, it maintains excellent functionality and speed. It also feels very durable, giving me peace of mind when carrying it between home and the office. Highly recommend this combination for demanding creative work!

Great product but unfortunately lost on a trip. Will be buying soon.

I don’t normally so reviews, but I got this and compared it to my other OWC, I’m more than please XL with the results!

Works with a new Samsung SSD I bought