OWC Express 1M2 2TB USB4 40Gb/s Portable NVMe SSD Storage Solution

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 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.

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!!!

Like a lot of people I was tempted recently by the Mac Mini M4 base model and its value proposition. Of course, only having a 256GB SSD for storage is a problem and Apple charges a ridiculous amount for additional storage so I decided to build an external drive. That's where this OWC 1M2 enclosure comes in. I researched the available enclosures and this one stands head and shoulders, or should I say aluminum fins above the competition. Unlike most others, the 1M2 is a solid block of aluminum with huge heat-dissipating fins that permits your m.2 nvme ssd module to run at full speed without throttling. It certainly does for the 2TB WD Black module I used, which runs warm when busy but does not throttle. Assembly of the 1M2 with your SSD module is easy plus there are lots of tutorials on YouTube. OWC includes a short Thunderbolt 4 cable which works perfectly. Of course you want to connect the 1M2 to one of the Thunderbolt 4 ports on the BACK of the Mac Mini, not the front ports which are much slower. My speed tests speak for themselves: 3200MB/s Write, 3145MB/s Read (Blackmagic benchmark). This is WAY faster than the onboard 256GB SSD and astonishingly good for an external drive. I relocated my user folder to the external disk (again lots of YouTube howtos, I recommend the ones by Mac Sound Solutions). It was easy to do and works extremely well. I am delighted with the 1M2 enclosure and recommend it without reservations. Don't be tempted to skimp and go with a cheap solution. You don't want heat buildup to throttle your disk speeds or worse, shorten the life of your SSD module. Packaging is 100% recyclable which is nice to see.

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.

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.

UPDATE: Still the best enclosure! Had a Predator GM7000 lying around and the 1M2 was once again the only USB4 enclosure that worked with it. It's the only USB4 enclosure good enough I bought it twice TL;DR: The OWC 1M2 is really good because it runs the coolest and is super reliable. The only downside is that replacing the SSD is a hassle once it’s seated inside. I’ve owned the Konyead, Zikedrive, Satechi, and Ugreen USB4 enclosures before purchasing the 1M2. I think the OWC 1M2 is the best out of the five, though not completely perfect. Quick explanation as to why I own all these: I work in film, and transferring multiple terabytes is common. USB4 drives let you do that extremely quickly. The only options for USB4 drives (as of writing) are the SanDisk or Glyph Pro series, which are horribly overpriced (and in SanDisk’s case, even destructive), or enclosures with the asm2464pd controller, which is currently the only one designed for USB4. While these enclosures aren’t cheap either, pairing them with an SSD like the WD SN850X, which has dropped massively in price, gives you fantastic speed for the cost. The OWC 1M2 is really big—bigger than even a 2.5" SATA enclosure (pictured in the second photo). USB4 enclosures are already large by M.2 enclosure standards, mainly for heat dissipation. PCIe Gen 4 SSDs can run as hot as 80°C or even 90°C if you’re using the SN850X, but the 1M2 excels at cooling. The entire enclosure is covered in large fins, and none of my other enclosures come close. Here's why that matters: all my other enclosures get very hot under load. The 1M2, being so over-the-top with cooling, only gets warm to the touch. That’s a huge win. With the others, I have to wait for them to cool down after big transfers. The 1M2 is always cool enough to keep going. In my setup, I use 4TB SN850X or FX900 Pro SSDs. For some reason, the only enclosure that works perfectly with the FX900 is the 1M2. I believe manufacturers write custom code for the 2464 controller, and OWC has written the best code for SSD compatibility. Moving between Windows and macOS, the 1M2 never drops a connection and handles full drive writes really well. The only other enclosure I own that’s equally reliable is the Zikedrive. The Satechi and Ugreen have some rare, forgivable edge cases, while the Konyead is basically toast. I also appreciate that the 1M2 came with reasonably new firmware for the 2464 controller, unlike the others, which I had to update. My only complaint is the design. Out of all the enclosures, the 1M2 seems the least portable. It has large rubber feet on the bottom, and unlike the others (except the Konyead), it’s designed to be upright only. That’s fine, but the annoying part is the screws—hidden behind the rubber feet that you have to tape on yourself. So, once your SSD is seated, replacing it requires removing the rubber feet and unscrewing everything again. Definitely make sure your SSD works 100% before taping the thing shut!

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!

Amaze! Amaze! Amaze! This is not just an external NVMe box. This is THE external NVMe disk box! The quality is surreal, unlike anything similar in the market. I installed a 970 Pro and the thermal dissipation even in heavy rendering work is really very good! I can record write speeds higher than my internal disk. I've tried many external disc boxes, but this one surpasses at all levels!

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!