USB 2.0
The USB 2.0 standard specifies an overall bandwidth of 480 Mbit/s shared between different transmission modes. uEye cameras use the USB 2.0 bulk mode for transmitting images. This mode uses error correction to ensure correct delivery of the image data, but does not guarantee a fixed bandwidth. To ensure error-free communication with all connected devices at all times, the maximum bandwidth for payload data is limited to 416 Mbit/s.
Theoretically, up to 50 MByte/s of data can be transmitted in this mode, but in practice, this value is hardly ever reached. A high-performance desktop PC can transmit about 40 MByte/s, most notebooks or embedded PC systems even less than that.
The overall bandwidth can be increased by the use of USB 2.0 expansion cards. These cards are available for the PCI and PCIe buses and have their own host controller chip.
Note on image content and bandwidth usage For USB cameras, you can use a white test image to check the camera's maximum load on the USB bus. Due to the transmission process, completely white camera images require a somewhat more bandwidth on the USB bus than completely black images. |
USB 3.0
Compared to USB 2.0, USB 3.0 offers a tenfold increased bandwidth of 5 Gbit/s, i.e. images can be transmitted with a bandwidth of 400 Mbytes/s.