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

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!

This is a USB4 Thunderbolt 3 case. Fast. Works great. I have 3. It is a little pricey at $99us. But thunderbolt cases are much more expensive than standard USB3.2 cases. I have 2 with the intergraded fan and one without the fan. My drives run so much cooler with the fan. For longevity of your drives I recommend the version with the fan. Just make sure you don't block the intake to the fan. Hooks up to my M2 iPad Pro perfectly. Fan is very quite I can barely hear it.

Very happy with this silent fan Thunderbolt enclosure from Acasis. Installation of WD Black SN770 2tb M.2 2280 NVMe was quick & easy and Blackmagic app showed sustained 2680 writes/2860 reads using included thunderbolt cable when attached to my Mac mini M4. These speeds are faster than internal drive in my Mac mini M4. Temp was acceptable with thermal pads provided with enclosure however I did add "icepc M.2 2280 SSD Pure Copper Heatsink Kit Cooler" and iStat menu app showed @ 10 degrees cooler temps compared with the thermal pads only. Probably cause the copper/thermal pad combo now has a very tight fit and contacts enclosure lid. Push button on enclosure allows fan to be turned on/off - but I leave it on (pushed in). Fan is very quiet and makes a big difference in cooling than with it off.

So far, works like a champ. I have a WD 8TB SSD (SN850X). Even with the fan off it stays relatively cool under heavy loads (> 1 hour at 1GB/s). With the fan on (which is dead quiet) it cooler than room temp under load. Solid slab of aluminum Very good packaging. I'm pleased. A bit pricey. I hope it keeps working this way.

Been using for about 2 months and have no issues or complaints other than not really knowing if the fan is turned off or on. Lost my high frequency hearing and have to guess @ the setting. Of course that does explain that the fan is quiet. Have a WD 2TB ssd and it works well. Actually the read & write is faster than my 256GB SSD in my Mac mini M4. No issues with heat -- I run TG Pro to monitor the temps and have been very satisfied with the performance. There are others out there but I went with Acacias based on reviews. No regrets at this time. Edit: 6 months in use -- Working thru an exchange of emails with support we determined the fan is not working. According to web site the warranty is for one year. I asked them about warranty gave them order number and other information. Their response and I quote -- "We have forwarded your question to the colleague in charge of Amazon, and they will contact you later to discuss the relevant matters. Please wait patiently. Thank you." I have been waiting one month so far! Changing my rating due to positive response from Accasis. They have replaced the failing unit. Still not putting at 5 stars due to the fact I had to contact via email several times to get warranty replacement.

Well built case for my WD_BLACK 2TB SN7100 NVMe SSD. Installation was a breeze (first one I'd ever done). SSD fit perfectly with only a screw and a rubber heat dissipation sticker to be applied, then slide the case close. Love the built in fan, which does help it cool down faster. A little heavy being all alloy but it's built like a tank. For the price, none of the other cases Id seen came with these features, so I felt it was a good deal. The USB4 cable was icing on the cake

The speed of this external SSD carrier is as advertised, even with a mid-grade SSD, which is impressive. However, I would recommend buying the non-fan version due to the exceptionally poor fan integration. The fan appears to be an afterthought, providing negligible value at best and a false sense of security at worst. First off, my fan doesn't even turn on. If it did, it would only blow air onto the carrier board rather than the SSD itself. This is a significant design flaw because the vent slots by the SSD are blocked by the cover, and there are no other openings for air to reach the SSD. As a result, there is almost no ventilation for the SSD, which I found to run very warm during heavy use. The included thermal sheets (0.5mm and 1.0mm strips) are a nice thought but do not effectively close the gap between the SSD and the cover. Moreover, since the SSD doesn't sit flat, the contact area would be minimal, rendering the thermal interface largely ineffective. I am an electrical engineer with significant experience in thermal designs. Zero stars for the fan integration. Five stars for the SSD integration, which has worked perfectly on my Mac. I did want to mention that the tool-less cover is really nice and works well. Despite the issues with the enclosure fan, I still think cooling is a good idea. To ensure my SSD runs cool and has a long life, I plan to 3D print a holder with an external fan. Currently, I have the cover off with a USB external fan providing circulation. In summary, while the speed performance and SSD integration are excellent, the enclosure fan integration is ineffective and not worth the extra cost. If you prioritize thermal management, consider opting for the non-fan version and finding a way to improve the cooling yourself.

This is my perfect enclosure! I am a professional video editor and I transfer video footage all the time using external drives when I need to be on the go. I can use it with pretty much all my devices to get the optimum speed since I paired it with a 2tb SK Hynix P41. I can get crazy fast speed on my M2 Pro Mac Mini using Thunderbolt 4 then use it on my Ryzen 7950x PC with the Gigabyte X870E Aorus Elite with USB4. Being backwards compatible I can then use it on my Dell laptop with USB3 or the Thunderbolt 3 port which ever is not being used since it charges through the type c connector. The fan is pretty much inaudible over room tone and can only hear it when holding it up to my ear. I keeps my NVME drive in the optimal operating temperature even under high loads which i can say about my other enclosures where I experiences thermal throttling. I know it's expensive but it is worth it to have such flexibility.