Both the USB 3 and the eSATA ports are fast with 3.5" and 2.5" HDDs.

The manual mentions nothing about the power button. Either it requires extreme pressure to turn on or off, or has to be held for 5 seconds, or some combination. I can't tell, but the operation is inconsistent and unpredictable.Using eSata makes it a one-drive dock. This is not mentioned anywhere. There is a single eSata port on the dock, which supports a single drive. You could have a dual eSata PciE card like PEXESAT322I with two connectors, but there is still only one eSata connector on the back of this dock.

I have this device connected via eSATA to a SATA card plugged into the PC motherboard. That card is a dual port eSATA card and it does support port multiplier, because of this Win11 on my PC does in fact see both drives. This is a good configuration for me. This device is an excellent match with the eSATA/SATA card I am using which is PEXESAT3221. Of course it is for a PCIe motherboard slot. If you are thinking of doing this make sure you have an open PCIe slot on your motherboard and if so get both. They will work perfectly and in this configuration they support RAID zero, which is what I was looking for. I hope this helps you.

I have several already but they are SATA II This one is III. That is double the Data Transfer Speed from 300 to 600 MB/s. Loving it, have Installed, Booted and ran several Linux Distros from an 2.5 SSD and runs af it were running directly from the onboard mboard SATA ports.copy data between drives. To install, test or run newer Linux Distros temporarily and not disturb the m.2 internal permanent distros, like Manjaro,OpenSuse, Fedora, Debian and ArchLinux based-like distros. I wish I had bought this one before the pandemic, price has increased but still worth it. I take SATA over USB hands down.

Bought this about 18 months ago, and it's a great dock for my ASUSTOR NAS which has both USB 3.0 and eSata. Much cheaper and more compact than the ASUSTOR expansion device. I bought this specifically for the eSata connection, which I find is generally more reliable and stable than USB 3.0, especially for large file transfers. Anyone using this with an ASUSTOR NAS should note it's not listed as a compatible product by ASUSTOR, although it works perfectly well with my AS6204T NAS. There is a sequence to get the eSata connection to be recognised by the NAS. Both the USB and eSata cables need to be connected to the NAS upon power up. After that, disconnect USB cable then eSata works fine. May take a little experimentation, but once you work out the initialisation sequence it works perfectly, no drop outs or disconnections. After power down or restart, the NAS will automatically recognise the eSata connection. Note: The NAS will recognise both drives as eSata1 an eSata2 (or USB1 or USB2 if using USB 3.0 connection). Hope this is helps anyone looking for a compatible eSata dock becuase I know there aren't many options out there.

I have a 13 year old computer with USB 2.0 (ugh) so the data transfer speeds are pretty poor. But it does have eSATA, and I thought I could pick up a hard drive to put in this docking station (A.K.A. "toaster") to take advantage of the eSATA speeds. I really wanted to like this StarTech docking station, but I feel like it's just not that reliable in eSATA mode. Using the USB cable, it's perfect, but that's not why I bought this model.The docking station did not always connect when I used eSATA. Using Disk Management on Windows 10, I could see the drive when using USB 2.0, but not always with eSATA. This was the start of my discomfort with the docking station. So USB 2.0 connections worked 100% of the time. In other words, if I plugged in the docking station (with hard drive mounted before I plugged in the cable, obviously) and used the USB cable, my old computer could see it and transfer files at the data cap allowed by USB 2.0. Same on newer computers using USB 3.0, this docking station is great. But as for eSATA...1st Screenshot: HWiNFOBut when I used eSATA, sometimes the computer recognized the docking station, sometimes it didn't. I tried two different SSDs, both simultaneously in the docking station and separately (just one drive at a time). They were both the same model: 1TB SanDisk Ultra III solid state drives. You can see it in the first screenshot, where I used HWiNFO to figure everything out.2nd Screenshot: Crystal DiskMarkWhen my computer recognized the drives while using eSATA, they worked at the advertised speed. See 2nd screenshot of Crystal DiskMark. It was satisfying to see this old computer move so (relatively) fast. But as I mentioned, sometimes my computer did not recognize the toaster (and therefore, the SSDs mounted in it). I tried to be as forgiving as possible, plugging the SSD in the docking station, then plugging the power on, then plugging the eSATA cable into the computer, THEN turning the computer on. Needless to say, there was MUCH powering on/off of my old computer. But it was still spotty. There was even one instance when the toaster disconnected from my computer MID-TRANSFER. Because it did this in the middle of moving files, that SSD became corrupted and I had to format. Luckily there was nothing important on there, but that's the main reason I returned the Star Tech Docking Station. But was it the old computer, or the station?Even though eSATA isn't as fast as USB 3.1, it's still better than USB 2.0. But the inconsistent recognition was no good. The thing is, I'm not sure if was my old computer, or the docking station that was the problem. I don't have any other computers old enough to still have eSATA ports, so there's no way to tell. I'm hesitant to blame StarTech, so I'm just trying to recount my experience using this old computer.I will say that it works just fine in USB 3.0 mode on a new computer. If you are looking for a docking station that can do that, buy the more recent StarTech models (without eSATA). But if you are looking at this model, chances are you are like me.Just keep this in mind if you are looking for a way to make use of your eSATA ports on your (probably very old) computer.Happy Shopping!

Instant installation on eSATA, well made and pleasant design. Works as described. Since I have only had the unit for about 6 weeks I cannot say anything about durability, but otherwise I am fully satisfied with this purchase.

Came very quickly well packed in original packaging with eSATA lead.Works well with both USB 3 (iMAC) and eSATA (PC). PC needed and additional card to recognise the port multiplier so that it would see both drive bays.Forms part of an archive/deep backup strategy.

Ya no hay pretexto para no respaldar toda esa información de la laptop o equipos de clientes,el equipo es muy rápido conectándolo a un puerto USB 3.0 y en Windows 10 con el UASP simplemente supero mis expectativas

Very quick when used with USB3 connections & other kit. eSata connection a little uncooperative at first, but now works well.

Quite surprised so many negative reviews. Not my experience, possibly due to other hardware or software differences.I purchased the StarTech.com USB 3.0 / eSATA Dual 2.5/3.5" SATA HDD Dock with UASP, part # SDOCK2U33EB. NOTE: two drive, not 4 drive capacity. As the name states, I use both 2.5' (SSDs) and 3.5"spinning drives with it. The Amazon purchase was in March 2015, perhaps updated from earlier. I've used the dock intermittently for 7 months.I ran Windows 8.1 Pro when purchased and Windows 10 Pro now. I use a tablet as a desktop (Microsoft Surface Pro 3, normally on the Surface Pro 3 dock station for its added USB, Ethernet, DisplayPort connections). So I'm using Windows, a purchased, not home made device, with USB version 3 connections, full power, no battery. That eliminates many who had (IMO: a self-inflicted) complaints.Next, I do not leave the dock connected and on all the time. It is simply an offline backup method so why leave it on risking possible (never happened yet) malware or virus. Offline is safer.As I started pen this, I completed a 50GB copy from my internal SSD to a slower SATA 3 Gb/s spinner, I'm now copying another folder 33GB in size. Done long ago. I see transfer speeds of 15 to 86 Mbps. Windows Explorer fully reported removal of a SSD (press down on left side ejector) then insertion of a 3.5" spinner. No freezes. No need to reboot etc.I do not award full 5 stars. The industry is awash with its SATA 1, SATA II, eSATA, PCIe, NVMe protocols with unrealistic speed ratings fully not relevant but repeated by manufacturers without a heads up to the uninformed consumer. They could do better. I have purchased and returned a competitors dock that did not transfer at USB 2 speeds so yes, this is better than other HDD docks.