UGREEN40Gbps M.2 NVMe SSD Enclosure, TB4 NVMe Enclosure with Cooling Fan, Aluminum M.2 Enclosure Support USB4 , UASP & TRIM, SSD Enclosure Compatible MacBook M1 M2 M3 M4 Pro/Max, Up to 3700MB/s

I like, it feels very well made and is a decent weightThe fan works and is quietWorks with my Time MachineThe included screw and attachment process - much preferred to a tool less design.Looks good - not an issue for me but it doesI don’t like, the heat. This is hot when in us and when idle. This may be down to the thermal pad, not doing a job - It is TOO THIN. Currently I have no other pads but have ordered a pack - update to followCurrently NOT attached 24/7 as I don’t wish to consistently run it hotLong term, I may get a couple of stainless steel blocks 80x30x30 and use those as heat soaksUpdate,Had this a week or so now, running cooler than it originally was, I suspect that’s due to the whole system now registered together. It does run faster when connected to my hub, a bit strange but not significant.

Summary: Looks good, feels good, performs amazing - IF YOU ENABLE WRITE CACHING!This SSD enclosure is amazing, its really fast (not quite the 40Gbps advertised limit - but it is expected not to hit this as this is a theoretical raw transfer rate that is also bidirectional), it also had a very good build quality, and feels very premium.To all those reading the comments and feeling torn due to the reviews that report slow write speeds - fear not! I also had my doubts; when testing the product for the first time (with a Kioxia gen 4 drive) I had the same issues (see picture 1). After doing a little digging I found that under Device Manager > Disk Drives > (NVME Drive in your enclosure) > Properties > Policies: "Enable write caching on this device" had defaulted to off. After turning this on (see picture 2), and testing again, the expected speeds instantly shot up to expected speeds (see pictures 3 and 4).Note: Enabling write caching this way is specific to Windows, I am unsure how this setting defaults on Apple devices, but I am confident that a synonymous setting exists.

Operates well with very fast NVMEs. Runs warm when idling and hot when working. The fan is quiet, almost silent. The rubber enclosure protector is not necessary unless to limit vibration, which I haven't experienced. It impedes air intake for the fan and reduces heat dissipation. Works fine without it.

It looks the part & seems well built (and quiet, I have read other people found it noisy).Inserted a Samsung 990 NVMe M.2 SSD 4TB PCIe 4.0 7450/6900.Only performed at 10Gbps (while it worked) NOT 40 Gbps.Tried CrystalDiskMark 8 (see image).Expected to see round 3600/3400 for the Samsung in this caddy.Tried read/write large video files - again only reached just under 10Gbps speed (960 MB/s read 750 MB/sec write).Windows refuses to recognise it now. - can't do anything with it (even on a 10Gbps port).Using Windows 11 Pro up to date on a Ryzen 16-core PC & all drivers up to date.Tried on both of the Asus motherboard Thunderbolt 4/USB4 ports.Another Thunderbolt 4 device I have works ok.The Samsung is ok, worked in a UGREEN 10Gbps caddy on a 10Gbps PC port at expected speeds for that caddy.(But of course that defeats the objective).Returned, and as usual Amazon handled it promptly (thanks).Going to try a "SSK 40Gbps M.2 NVMe SSD Enclosure, USB4 NVMe Caddy USB C for Thunderbolt 3/4".UPDATE: 9th March 2025Windows 11 indicates that it's not a compatible USB4 device.While I only give 1 star that's because the device does not work for my PC - it may work for you.The device itself is well built and, I suspect, very capable if you have the right USB4 port (or one labelled 40Gbps).It's has taken some time to determine what is going on, but it boils down to this ...USB4 can be either 20 Gbps or 40 Gbps, depending on thespecific device and its capabilities; the standard supportsboth speeds, with 40 Gbps being the maximum transfer rateachievable with the latest USB4 technology.Key points about USB4 speeds:20 Gbps: Considered a "base" speed for many USB4 devices.40 Gbps: The highest possible data transfer rate for USB4,achieved with specific compatible devices and cables.NB: In the future the standards talk about 80GbpsI think the issue I have isEITHER my ports are a USB4 20Gbps port (even though it's Thunderbolt 4 40Gbps),OR it's the mine field of "compatible devices".My Asus motherboard (on a Ryan 16-core) has an early adoption of Thunderbolt 4/USB4 ports.My Thunderbolt 4 & 3 devices work perfectly on the Thunderbolt 4 ports.Also any USB 3 Gen 2 (10Gbps) device works as expected (as does any 5Gbps USB device).I suspect USB 3 Gen 2x2 (20 Gbps) will work - yet to be confirmed.The problem is USB4 devices only - and the USB standards - they are confusing.I notice that recent Asus motherboards describe ports as "10Gbps" or "20Gbps" which avoids confusion.(Not sure if that's because of new standards).Any 40Gbps NVMe caddy is a gamble for Windows users depending on the capability of your PC USB4 port.I don't know about Mac users.Returning the item to Amazon (whose service has always been excellent for me).I have two UGREEN 10Gbps M.2 NVme caddy and they work perfectly (speed as expected).I have tried SSK 40Gbps M.2 NVMe SSD Enclosure (as mentioned earlier) and it has the same issue as this product.So, I will now try a UGREEN M.2 NVMe Enclosure, 20Gbps - I suspect it will work perfectly.

I bought this as an alternative to paying for increased internal storage from Apple - the Mac mini m4 base spec is really good value for money, until you start to increase the amount of internal storage, at which point you’re paying an extra £400 for 1tb of internal storage. Pairing this with the 256gb configuration, a 1tb branded fast Nvme drive (around £75) means you get way more storage without compromising on speed - the external drive runs as fast or faster than the internal. The enclosure comes with a thermal pad and so far I’ve not experienced any issues running my sample library for Ableton live from it. I’ve never heard it make any noise whatsoever. The build quality feels good and the device is small enough that it can be hidden behind the Mac mini itself.I was pleased to see it came with everything you need to install the drive and use immediately (good instructions, thunderbolt/usb4 cable, thermal pad and a small screwdriver).If I run out of storage I’d buy this again.