Hi Leonard,
Regarding your questions, in order:
1. Perhaps the issue is in fact a bandwidth / hub topology limitation (and possibly driver scheduling) rather than strictly a defect of the board you’re using. Since you affirm that three streams run fine but the fourth fails consistently, that suggests that the fourth device hit some kind of resource limitation (not necessarily CPU/GPU since those remain normal). There are other forum threads for the Orin family where users run into similar problems with multiple USB3/UVC cameras simultaneously. For example: Multiple USB 3.0 Camera Issues , USB3 Bandwidth Issue with Dual High-Speed Cameras on Jetson Orin & Nano , Multiple USB cameras limited to 10Gb/s total . For four 720p@30 MJPG streams the real USB usage may be modest, but scheduling or hub sharing may still impose a limit.
2. There is no public information confirming that the reference Orin NX devkit works flawlessly with exactly 4×720p@30fps MJPG simultaneously. Users report issues at that scale, the safer assumption is maybe, but you should treat it as not guaranteed. In more general threads (Orin / Orin Nano / AGX) users struggle even with two or three cameras at higher resolution or high framerate. For example, the previously mentioned post Multiple USB 3.0 Camera Issues
3. There are some suggestions in the web (for example modifying uvcvideo module bandwidth caps, using different USB hubs by switching ports, using powered hubs, reducing device bandwidth) but these are mostly workarounds, there is no guarantee of a “fix” that will always allow the 4th camera to work.
4. Possibly, but once again, not guaranteed. Upgrading JetPack may help if there are driver improvements for the USB/xHCI/uvcvideo stack. Using the NVIDIA official carrier board may offer better port/hub layout (less sharing of root hubs) or better documented behavior. However, the underlying USB Root Hub / xHCI controller hardware limitation likely remains, so performance may still be constrained.
At RidgeRun we can help you solve your issue. Please let me know if you have any questions or comments.
Embedded Software Engineer
RidgeRun | https://www.ridgerun.com/
Contact us: support@ridgerun.com
Developers wiki: https://developer.ridgerun.com/