Review on 2.5G Ethernet to USB Adapter, CableCreation USB 3.0 Gigabit LAN Dongle, Wired Network to USB Converter, Latest RJ45 to USB Adapter for MacBook Windows 10,8.1, macOS X 10.6-10.15, Black by Brandon Gaines

Summary: As far as I can tell, this USB Ethernet adapter works fine. I would recommend using the latest driver from the Realtek website. My initial review and subsequent update is below. So I plugged in this 2.5 Gigabit Ethernet adapter and made sure it negotiated the 2.5GbE uplink to my TrendNet 10GbE switch. It then initiated the transfer of a single 8GB zip file over the network. Result? 35-45MB/s. What? For reference, this is much worse than Gigabit Ethernet, which can offer speeds of around 110MB/s. At first I thought that maybe the USB 3.0 port on my test computer was defective. So I tried it from another computer. Same result. It didn't matter which USB 3.x port it was, and it didn't matter if I was connecting to my Trendnet 10GbE switch or Cisco 1GbE switch. My network file server is connected via a 10GbE uplink and uses solid state storage. It easily transfers large files at 112-113MB/s over Gigabit Ethernet and 1GB/s over 10GbE. So it's obviously not a bottleneck. I will ask Revain to send me a new one, I hope it works better. Update: So the replacement adapter arrived and I had time to do some more testing last night. Rebooted and Windows removed any existing drivers, then installed the latest versions from the Realtek website. The 40-45 MB/s speed problem went away and instead I got 8-12 MB/s when trying to upload a file from my file. Server. It was WTF! Moment and plugged in the original adapter and it behaved the same way. Download 8-12MB/s. Then I tried uploading the file to a file server and it showed a consistent 270-280 MB/s. I tried downloading from a file server. And again 8-12 MB/s. Same behavior on both adapters. The topology is as follows: test machine <--2.5GbE link--> Trendnet TEG-7080ES switch <--10GbE link--> FreeNAS file server. something else is wrong. In any case, it's beyond my understanding at the moment. I verified that the CableCreation 2.5GbE USB adapters were not to blame by configuring the Aquantia AQN-107 10GbE chip built into my motherboard for a 2.5Gb/s connection, and the same problem occurred. Full download speed and 20-22MB/s upload to/from file server. Tried 5Gbps and same thing. Interestingly, this problem does not occur at Gigabit Ethernet speeds. That's a solid 112 MB/s round trip for a full day. PC <--1GbE link--> TEG-7080ES switch <--10GbE link--> GoodPC file server <--2.5GbE link--> TEG switch -7080ES < --10-GbE-Link--> File Server SlowestPC <--link 5.0 GbE--> TEG-7080ES Switch <--link 10 GbE--> File Server SlowerPC <--link 10 GbE--> TEG Switch -7080ES <-- Link 10 GbE--> SPEEEDTLDR File Server: I may have had a driver problem before. However, I couldn't reproduce the original 45 MB/s issue. As far as I can tell, USB adapters work just fine. More importantly, even though it's specifically advertised as NBASE-T compliant, I've found my switch doesn't work well with mixed multi-gigabit signals.