Fortunately, many cables have the USB standard printed somewhere along the cord. Since USB 1.0, 1.1, 2.0, and 3.0 cables all look the same, it can be difficult to know what standard a USB cable supports. Important: If you connect a USB 2.0 or USB 3.0 external hard drive to a computer with a USB 2.0 or 3.0 port and it seems slow, it could be due to a slow cable, such as a USB 1.1 cable.

Similarly, if the same device is connected to a USB 1.1 port, it can only transfer data at 12 Mbps. For example, a USB 2.0 device connected to a USB 3.0 port will only transmit data at a maximum rate of 480 Mbps, which is one tenth the speed of USB 3.0's 4.8 Gbps maximum data transfer rate.

While USB devices are usually compatible with multiple USB standards, they will only communicate at the lowest speed of the connected components. Likewise, you can connect a USB 1.1 device to a computer with a USB 2.0 port, and it will function correctly. For example, you can connect a USB 2.0 device to a computer with a USB 3.0 port and it will work just fine. This means newer USB standards are compatible with older devices. The USB interface was designed to be backwards-compatible. Any of these three components could be the cause of a slow USB connection. Answer: When you connect a device to your computer via USB, there are typically three components вЂ“ 1) the computer, 2) the device connected to your computer, and 3) the USB cable.

Usb 3 transfer rate really slow