X2 USB 3.0 Type C Gen I & Type A Dual Bay 3.5" HDD Enclosure 5 Gbps Max w/RAID 0 & RAID 1

Only good to 3TB but that was all I needed as I had two Toshiba 3TB 7200 RPM HDDs doing nothing. Set it up in RAID 1, mirrored, and have had no problems so far in 4 months. Quality seems good and the price was really good. Sustained read/write speeds to/from an M.2 VIA Technology NVMe SSD are ~170MB/s & ~150MB/s for a 33GB file. My NAS is only about 8MB/s.

I set this up with two 3TB drives left from a maintenance swap from my NAS. I had a third drive that I set up in a single external housing. The transfer rate (write) subjectively seemed about 25% slower than the single drive in an external housing regardless of the mode I selected which leads me to believe that the internal controller is a bit slow. This would make a suitable backup drive or general storage, I prefer to set up backups as RAID1 devices for redundancy and this supports RAID1 along with RAID0, JBOD and 'normal' which just means two separate drives. The overall quality of the housing is solid, especially considering the price and it looks attractive as well (except for the Serial ATA logo on the front, I mean, seriously... who cares?). The only concern I had was that after installing the drives on the tray the screw holes for the screws that hold the housing together didn't line up quite right with the threads in the aluminum housing and were offset about 1/32". I had to squeeze the case while aligning the screws for them to thread in. This doesn't appear to be a problem after it is together again but I took it apart several times trying to determine the cause for this and was unable to. Also, minor point since you generally only do this once when you install the drives, in order to change the drive mode the DIP switches are inside the housing and when you change the mode you also have to press a reset button for about 10 seconds which I missed in the instructions the first time I changed it, so I had to take it apart again to reset the controller so that it recognized the new mode.I tested this in several modes on an iMac and all seemed to work without issue other than the speed of transfer I mentioned earlier.I did not explicitly check the power saving function since it really isn't something I'm concerned about and the manual says that if you have problems just power cycle it with the switch. Others have noted an issue with this if you are using a Mac. However, I did have a setting enabled that would power down disks if possible. As I was writing this review I noticed that the fan had shut off and the drives did shut down. When I copied a file to it in this state it took a rather long time to 'wake it up' again. I didn't actually time it but it took probably 20-30 seconds before the drives spun up again and the fan turned on and then a little while longer before the file started copying. Just something to be aware of - don't get impatient.The fan is a bit on the loud side as well. There is a 40mm fan in the back that runs whenever the unit is on and not in power save mode. There is a switch to turn it off but heat is the death of electronics, especially mechanical drives so I would hesitate to turn the fan off unless you absolutely needed to quiet things. The fan switch is recessed and it was set to 'on' so I would take that as a sign that HornetTek would like to see it running unless absolutely necessary. A thermal sensor would have been a nice feature but consider the price you are paying for this.Overall it's a decent external housing with RAID support as long as you don't rely on high transfer rates. As to long term reliability I can't really say.One other little oddity... there is what appears to be a power button on the front of the device but all it is is the light to indicate that it is turned on. You can even push it and it feels like it is doing something but it doesn't.I gave it three stars because for the price it seems to be a good value if you can live with the quirks.

Fan is very loud. Using it without the fan on for now. Time will tell if it will be okay without the fan running.... Otherwise a very good enclosure for my 2 3tb hard drives!UPDATE: One hard drive doesn't work. Swapped the two hard drives and now the other one doesn't work. The side of the enclosure that works is starting to fail, as well.... Very disappointed...

using as a cloned HDD and it works well.

This is a nice looking unit, hardware well engineered, and so far with one one exception has been working well. I'm using it on a mac where the drive is configured with RAID off, so it just looks like two separate disks. I then use the Mac Disk Utility to make a RAID. All well and good.But then I start getting weird problems and have to power cycle the unit, or reboot my Mac. Tracked it down to the System Preferences "Put hard disks to sleep when possible" checkbox in Energy settings. If that is ON, then this unit (unlike the older Rosewill dual disk case) hangs or gets into some weird state.Regardless of this hang, that checkbox probably doesn't do much with modern drives, and so I just unchecked it and now all is well.I ding the company for tech support as I messaged them twice, way over a week ago, and heard nothing. I used their web form, then sent them a direct email - nothing.

I've had this unit for a year or two now and have had one drive fail and another that might be on its way out. Disconnects regularly on my mac (which is how the first drive failed). So it works ok in a pinch, but can't recommend for regular use.

I've had one of these for several years now and it's been perfectly reliable. So when i needed another one i was delighted to see the same model was still available. Other reviews commented on the fan volume, but since i already had one i figured these people were just more sensitive to sound than i am. I always have music playing and never notice the fan in the one I already have. So when i got the new one up and running I was surprised to find that, yes, it is noticeably louder than my other one. Using a not entirely accurate decibel program on my phone, it measured to be about 8db louder than the older one. And that appears to be enough difference for me to hear and notice that this thing is always on. I could turn the fan off, but while i can hear it, it doesn't bother me all that much. I wish it had a temperature control though. Since this unit sits idle 90% of the time as it's only used for backups, it's probably not all that hot in there. But still, I recommend this to anyone that wants to build a 2 disk array USB drive and isn't bothered by the hum in the background. Or you can just turn the fan off.One other thing of note, the instructions aren't entirely clear about initially setting up an array. They say "when switching raid type, press and hold the reset button". What they don't say is that you have to do this for the initial install as well. I guess you are "switching" from not set up to set up. LOL

I put in some old WD discs. The enclosure works, but this is JBOD. I am not sure what to use it for except copying old stuff from them. The worst part, it is slow. Very - not USB3 slow.