ACASIS USB4 NVMe SSD Enclosure with Cooling Fan,40Gbps M.2 NVMe Enclosure for MacBook M.2 Enclosure Tool-Free Support M/B+M Key Size 2230/2242/2260/2280 Compatible for Thunderbolt 3/4/USB4/3.2/3.1

When I originally received this enclosure it was missing the heat pad and the usb-c cable that was included was short and only capable of usb 2 speed so when I wrote my original review I complained about the low data speed (30MB/s) and the missing heat pads and only gave the product 3 stars. The enclosure was fine, the accessories were bad or missing. After a long email correspondence with Acacias Customer Support, which included pictures of what I received, they told me that the cable I got was not their cable and so I thought I might have received a device that had been shipped to someone else and returned without the heat pad and with a useless usb cable, and I ordered a replacement. The Acacias product package was not sealed so it was not possible to tell if it already had been opened. The replacement just came in and when I opened the package (it was also not sealed) it contained a proper Thunderbolt 4 cable and the heat pad, and when I tested it I received the kind of speeds I expected - about 2800 MB/s using the WD 1 TB 2280 memory. That makes it clear that I received the bad usb cable due to my original order having been returned to Amazon by another customer and not due to the fault of the vendor, so I have revised my review. This enclosure works very well, although it does get very warm and probably needs a cooling fan as well as the included heat pads. The speeds are everything I expected and the included Thunderbolt cable works properly. It is a bit short for me, but it is the length specified in the product description. I am happy with the replacement and feel capable of recommending it. If you want external drive speeds close to the speed of your computer memory consider this enclosure. --------------- I recently bought the version of this enclosure that contains a fan for cooling and when I tried to leave a review Amazon told me that I had already reviewed it, although that version was the version without the fan, so I am adding this review to the end of the original review. While the original enclosure is a great way of adding high speed memory to your system it suffered from one drawback and that is it needs cooling. I solved the problem by buying a small muffin fan and attaching it to the enclosure and, with that, it ran cool and I had no heat issues. This new enclosure solves that problem and I have replaced the version without the fan with this one. This is a first class enclosure with transfer speeds as high, if not higher, than the internal memory of my Mac M2 Mini. Repeated use of the Black Magic speed app showed no slowdowns due to thermal throttling so it is dependable and fast, even after long use. Thee are some minor issues. First, the manual that comes with the enclosure is the manual for the version without the fan so it contains no information about the cooling fan. There is a small button on the side of the enclosure to turn the fan on and off, but even when holding the unit next to my face I could not feel air moving. To be sure that the fan was working I had to hold it next to my ear, and I could hear it running. There is also a small LED on the side of the enclosure and it shows a constant light when the fan is running and a blinking light when the fan is not running. I have picked up the enclosure during the day and found it to be slightly warm while the old enclosure was hot to the touch without the muffin fan I attached. This is a great enclosure and I believe that it deserves the 5 stars I have given it.

I recommend

Works as advised. Not quite the speeds listed but that could be more to do with my setup and devices.

Excellent little enclosure. No overheating or throttling & very fast file transfer speed for below Crucial SSD. I put my Crucial P3 Plus 4TB M.2 NVMe SSD into this (whilst waiting to buy a 4TB Acer Predator GM7000 or possibly different if prices improve). The Crucial seems to run at max speed when connected to the Thunderbolt 4 port on MSI GE78HX laptop A transfer of over 900GB of media files was blazingly fast & took no time at all. Unfortunately I just needed my files moved asap so didn't actually time it, nor got around to benchmarking via a utility to fully test but will do so when I have more time just to actually see how well it performs. Considering the Crucial is only rated for 4800MBs I believe the enclosure will have no trouble with higher speed SSDs. ONE THING TO NOTE- The Crucial has it's NAND & Controller etc all on 1 side so I just placed a thermal pad on that side ensuring it contacts the lid & at most it became warm with no worries about overheating. With faster SSDs & particularly double sided like the Acer GN7000 it will defo get more heat but considering how well it does with the Crucial I believe it'll manage very nicely. USB-C Thunderbolt cable provided is high quality & it's very nice to see a 500mm length instead of the usual pathetically short cables most supply. Hopefully this'll continue to perform well into the future but as it currently stands I can highly recommend if it can be found for a reasonable price (under £90). Will be keeping an eye on Black Friday & grab at lease 1 more if dropped to a bargain price.

My 2019 5K iMac had been crawling along on its original failing 2 TB Fusion Drive. Cold boot times were routinely 5–8 minutes, and even opening apps felt like 2010 all over again. I had heard success stories of opting for an external drive to replace the failing Fusion Drive and bought the ACASIS Thunderbolt 3 enclosure + Samsung 990 PRO 2 TB combo. Result: - Cold boot to login screen: 25 seconds - Fully usable desktop: 40 seconds - Parallels Desktop now runs Windows 11 + Debian Linux side-by-side with zero lag (impossible before) - Large file transfers are instant - Maintained 2 TB of storage Install was straightforward: cloned my drive, set the external as startup disk, and it just worked. The built-in fan is whisper-quiet but keeps the 990 PRO cool even under heavy load. Build quality is excellent – solid aluminum, short Thunderbolt cable included, and the little fan toggle is a nice touch. If you have an older Intel iMac that’s dragging its feet, this might be the single best upgrade you can make in 2025. Zero regrets – my six-year-old machine feels brand new again. Highly recommended!