LEARNED IT · 08/26
USB 3.0 isn't a performance choice — without it the mode doesn't exist
On a USB 2.0 link the SV205 doesn't advertise its max-res YUYV mode at all. There's no error and no dropped-frame warning, so it reads as a camera limitation.
Uncompressed YUYV 3264x2160 at 15 fps needs roughly 212 MB/s. USB 2.0 tops out well below that, and the camera's response is to omit the mode from its descriptor rather than offer it and fail.
So the symptom is: the capture app only lists lower resolutions. Nothing anywhere says "cable". It looks like partial Linux support, or an overstated spec.
Check the link speed, not the app:
cat /sys/bus/usb/devices/*/speed # 5000 = USB 3.0, 480 = USB 2.0
Needs the blue port and a 3.0-rated cable — a 2.0 cable in a 3.0 port negotiates 480. Confirmed working at 14.9 fps once both were right.
Generalises past this camera: "the device doesn't offer it" is not evidence the device can't do it. Check the link before you believe the capability list.