OWC 2TB Express 1M2 Portable NVMe Thunderbolt (USB-C) SSD USB4 Ultra Fast External SSD Drive with Aluminum Heat Sink Enclosure

Perfect for Mac Mini M4 base model
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.

OWC Express 1M2 – Thunderbolt/USB4 – Best in Class for Mac M4 Pro
As Adverticed, this unit goes as fast as USB4 allows it. +3500mb/s in Write and +3300mb/s Read.Tested on a Macbook Pro M4 Pro.Also, no mecanical parts what so ever, no fans that can potencially fail on the long run.The Heat Radiator works really well and its a solid piece of aluminum that gets warm to the touch.5 out 5 Stars.

Excellent build quality
This is by far the fastest external enclosure I have used. I have consistently gotten higher throughput than with any other enclosure. As high as 600-700 meg per second. Also, the build quality inspires confidence as once this is assembled, it feels very solid and beefy. The heatsink is very substantial and allows continuous use without getting too hot (warm to the touch at most after an hour.)

Probably the best USB4 enclosure
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!

Using a Mac Mini with M4 Pro, with WD 850X 2TB, I was able to get 3500Mb R/W on avg.The enclosure is always warm, even on idle.

Parfaitement adapté à mon besoin pour accueillir un disque SSD qui va bien.

This passive heat sink makes your M2 ssd perform the way you expect even when it is in heavy use. I have tried a few and this is by far the best ssd enclosure I have found.