When using multiple USB cameras simultaneously on a single computer, there are three points to consider:
- Choice of cameras
- Camera limit
- CPU capacity
Please note that at the end of the explanation, I will introduce USB cameras that allow you to use multiple cameras simultaneously on a single computer. Please continue reading for more information.
■ It is possible to use multiple cameras with one PC. However, depending on the camera, it may not be possible to use the same model.
(In the case of the same model, the driver software will be the same and may interfere.)
< The upper limit of camera quantity>
Let’s first consider the bandwidth.
If we are operating a single 3-megapixel camera at 10 frames per second, the data rate would be 30 megabytes per second (3 megapixels × 10 fps = 30 MB/s).
(Each pixel calculated as one byte)
<In the case of a USB 2.0 camera>
The bandwidth of USB 2.0 is 480 Mbps, but the maximum achievable speed in bulk transfer mode is specified to be approximately 52 MB/s. Therefore, simultaneous usage of two or more cameras is not possible (30 MB/s × 2 > 52 MB/s)
<In the case of a USB 3.0 camera>
The bandwidth of USB 3.0 is 5 Gbps. However, according to specifications, 8-bit data is converted into a 10-bit signal and transmitted. Therefore, the actual data transfer speed is theoretically limited to 4 Gbps, which is equivalent to 500 MB/s. As a result, it is possible to use a maximum of 16 cameras simultaneously, calculated as 500 MB/s divided by 30 MB/s. (This is strictly considering bandwidth, but in reality, the presence of control data communication and other factors may limit the number of cameras to less than 16.)
If you plan to use multiple cameras, it is advisable to utilize USB 3.0 for optimal performance.
<CPU performance >
Processing multiple camera images simultaneously is expected to impose a substantial burden on the CPU. While the actual impact may vary depending on the software used, there is no alternative but to test it in practice. In essence, it is advisable to employ a CPU with high processing capabilities.
