USB4 hasn’t exactly taken off as yet, largely due to a shortage of devices in the market and with a limited number of device controllers, the competition in the market is also slow. With Thunderbolt compatibility, there are plenty of USB4 compatible hosts out there though, even though you only get 32 Gbps rather than 40 Gbps of data throughput when a USB4 device is connected to Thunderbolt 3 or 4, although Thunderbolt 5 will allow for the full 40 Gbps. A company called ADT-Link has launched a product it calls the UT3G which is pretty much a retail ready bridge solution that allows techies and tinkerers to try out whatever PCIe devices they have over USB4. The adapter has a full-length PCIe x16 slot, but it’s limited to a four lane PCIe interface which is compatible with PCIe 4.0, albeit not at the full 64 Gbps that such an interface can deliver.
In addition to the USB4 Type-C port on the PCB there’s a standard 24-pin ATX power supply connector for power, which means that this isn’t really a portable solution. However, the company has tested the UT3G with various graphics cards from both AMD and NVIDIA to make sure you can use it as an external graphics card dock. The UT3G has also been tested to be compatible with Windows, Linux and macOS, although macOS is limited to AMD GPUs. The board is built around the ASMedia ASM2464PD USB4 to PCIe 4.0 bridge and this shouldn’t come as a surprise, as so far this is the only such device controller. ADT-Link doesn’t appear to be selling the UT3G to consumers, but it can be picked up online from DFRobot starting at US$129 for a single unit.