ACASIS80Gbps M.2 NVMe SSD Enclosure, with Cooling Fan, Compatible with Thunderbolt5/USB4 V2.0, Back Compatible with Thunderbolt4/3/USB4 V1.0, USB3.2/3.1/3.0, Support SSD B+M M-Key (TB501 Pro)

Speed test Apple iMac 2019 Thunderbolt 3 Sequoia 15.3.2 -- Compare new ACASIS 80Gbps TB501 Pro vs 40Gbps TBU405 PRO read write IO -- I have three TBU405 PRO I purchased new on Amazon and love the speed and reliability I get off them through TB3 -- I bought the latest TBU405 PRO and ran AJA System test -- I used the same newer WD BLACK SN850X 2TB SSD NVMe 2 in both enclosures.See my photos:the older 40Gbps TBU405 PRO gave me the familiar 2593Mbs write and 2736MBs readthe new 80Gbps TB501 PRO gave me dismal 900Mbs write and 900MBs readConclusion:Unless you have Thunderbolt 5 hardware on a Mac computer -- stick with the TBU405 PRO -- I saw some vague reference to this Thunderbolt 3-4 disclaimer in the ACASIS product description but it wasn't conclusive -- hope this real world test answers the question for you -- TB3 (and probably TB4) run at 10 Gbps speeds on the Apple Macintosh Computer 2019 iMac I tested (just like the ACASIS TB501 Pro product description says).In other words:the new 80Gbps TB501 Pro is a Thunderbolt 5 ONLY enclosure if you expect full TB5 speeds and reliability -- it only delivers 10 Gbps speeds on TB3 and TB4 hardware.My three TBU405 PRO enclosures all get the crazy good speeds in my screenshot -- except for Samsung which is slower in the external enclosure, but the Samsung 970 EVO PLUS M2 SSD gets the crazy good speeds installed internally -- the WD BLUE and WD BLACK NVMe drives give me the best sustained speeds I've tested on macOS in these TBU405 PROs -- not sure how reliable the Western Digital SSD are in the long run, I do have the most confidence in the Samsung, but I only use them internally now as Samsung tech support say their NVMe PCIe M.2 SSD are for internal use only.Blackmagic Disk Speed Test app gave similar results

This case just works! It’s easy to add an NVMe chip to and the TB 5 speeds are blistering. An internal fan, if needed, keeps it cool.

TLDR/ I Returned It!I recently purchased the Acasis 80 Gbps Thunderbolt 5 NVMe SSD enclosure to go with a new Apple Mac Mini Pro M4 to take advantage of the Thunderbolt 5 ports for video editing work.I tested it with a 1 TB Western Digital Black SN850X M.2 NVMe SSD. Black Magic showed the read and write speeds for this configuration to closely rival the internal SSD speeds of the Mac Mini, which was more than twice as fast as the 40 Gbps Acasis Thunderbolt 4 enclosure that I use on my MacBook Pro M2.I thought I was set, but decided to do some real world testing by transferring a 7 GB and an 11 GB folder to the enclosure. This usually takes seconds on my MBP M2 laptop. So I was really surprised and disappointed at how slowly it took to transfer the 7 GB.… closer to a minute ! The 11 GB folder never even finished after waiting several minutes!As a sanity check I connected it to the MacBook Pro’s Thunderbolt 4 port and got the same results. And although there were no error messages, the behavior seemed almost as if it was losing connection and then trying to resume from where it left off.Running the same test with my Acasis Thunderbolt 4 enclosure on the Mac Mini only took seconds for both 7 and 11 GB files. The problem is definitely with the new 80 Gbps enclosure.So, in summary, I returned this very expensive but disappointingly inoperative enclosure. Lesson learned … believe the other reviews, especially at this price point. For the record, I have several other Acasis 40 Gbps enclosures and they all work very well. I incorrectly assumed that this particular one from the same brand would follow suit.As another reviewer mentioned, perhaps the technology isn’t quite matured yet, so I’ll have to wait until something more reliable comes out.

This is my third purchase of an Acasis Thunderbolt product.Some background: I’ve been using their products for years. Pretty reliable. The first purchase was a Thunderbolt 3 M.2 enclosure. The second purchase two Thunderbolt 4 Dual M.2 enclosures. I used both Dual M.2 enclosures to create a RAID 0 array. The built in fan on these Dual M.2 enclosures have an annoying pitch so I bought a separate 8” fan to blow directly on it. I achieved stable speeds around 5000 MB/s.The Thunderbolt 5 Enclosure:I bought four of these to replace my aforementioned dual M.2 enclosures. This for me is a temporary fix until they come out better enclosures. That said my use case is niche and regular users will be satisfied with this. The built in fan is VERY quiet, I can’t hear it. I have to literally put my ear up to it. That’s great. There is a button to turn this fan on and off - that’s cool (no pun intended). But I’ve noticed the fan will turn off on its own sometimes after extended use and there’s no light to indicate if the fan is on or off (although it's only turned off on it's own once, might be a fluke). They did such a good job with the fan that I feel like a light indicator would help. Initial speeds for my RAID 0 are phenomenal, but for some reason it always trickles down aggressively. For my RAID 0, my initial write speed was 17,000 MB/s and read was 14,000 MB/s. After a few hours, it’s greatly reduced. Write stabilized between 6500 and 7500 MB/s and read between 12,500 to 14,000 MB/s. It’s still REALLY fast, but I can’t seem to keep the initial speeds. I am guessing this is because it doesn’t have its own dedicated power source like the dual M.2 enclosures. Without the RAID, just as individual enclosures you’re looking at about 5,000 to 5500 MB/s. I have not tested an individual enclosure after hours of use, but the RAID I set up is not ever turned off and it holds up fine. I would argue that a RAID is an adequate stress test to determine if the product is good for most users. Given that it’s been holding up for days at this point, I can safely recommend it.My set up is a Mac Studio M3 Ultra (32C/80C) 512GB Memory and 4TB storage.

Great build quality. Works well with 4TB WD850X. Amazed at how quickly I was able to transfer 300 GB of photos. With the coupon discount at $240 OI think that it represented a good value. Would have liked better instructions.