USB Type-A or Type-C to 5-Gigabit Ethernet Adapter [10/100/1000/2500/5000 Mbps]

It's the same thing as the QNA-UC5G1T from QNAP, but at about half the price (I got the Sabrent one for about $50 when the QNAP one was around $110). For both version you want to use the AQC111U driver from Marvell. Both devices use it, have the same features, and perform the same.I have both, and I personally think the Sabrent one is even better because it does not appear to get as hot as the QNAP one.

I've tried various other 2.5GbE class USB NICs, and this worked out of the box as intended. For those seeking 5GbE speed: do note that you can't quite reach it due to USB protocol overhead.

Box, manual, and device itself all say "5 GbE". When I plug it in, it claims to only be a 2.5Gbit device. And even with a high-quality Cat 6E cable that gets 10 Gbit to my other device's 10 Gbit port, it will only connect at 1 Gbit. I have tried plugging in to two different switches, 2.5 GbE, 5GbE and 10GbE capable ports, with multiple different cables, and 1 GbE is the fastest it connects.If I even got the 2.5GbE it tells the OS it supports, it would be tolerable, but I can't even get that, much less the 5 GbE it says on the outside and on the box it supports.-- Update: Tried it in Windows. In Windows, it claims to be 5GbE, but only connects at 2.5GbE.

Replaced a Killer 2.5GbE adapter that was flakey (which apparently is the norm for them now sadly) and this worked out of the box, no issues, haven’t had to think about it since install. I have it connected to a mini itx board that has USB C but no available internal PCIe slot for a 10GbE adapter. This is the next best thing.

Context: I was a network engineer for years before moving into other areas of technology and moving into management. I am not the stone-cold expert I once was, but my tcpip and networking chops are still first-rate even within technology circles.I've used hundreds of usb network adapters over the last decade. I've hacked firmware and drivers to get them to work in kali and performed pen-testing. I've aggregated them in strange configurations to get better throughput. This is easily one of the worst adapters I've EVER used, for the following reasons:1. This adapter does not perform consistently with a given set of settings. Results are not reproducible. the very first time I plugged this in, I got 2.5g speeds. This was cool, but the adapter would reset whenever there was a sustained. Having flow control on at the switch fixed this for a bit. Then I couldn't even get 1g speeds despite it reading a 2.5 g link. Then I realized this only works on Big Sur if you disable sip -- I did that and installed the driver and have never gotten even 1G speeds again. I spent an entire day testing every combination of settings on both the switch and the adapter. At best I can get 1G speed and usually half that2. The fact the driver requires SIP to be disabled is pretty unacceptable. You have to disable useful security features even to use this on a mac which is irresponsible on behalf of the manufacturer.3. This isn't really a 5g adapter even on paper. It has a 5Gbe controller, but it's limited to ~3 due to the usb interface it uses. It's pretty hard to imagine how that happened except for gross negligence.Honestly, buy ANY other adapter. Or just throw $70 in the garbage and you'll still be ahead the frustration of using this.