1. How long can the 256GB SD card record?

Bitrate affects video quality and the size of recording files. In general, the higher the bitrate is, the better the image and audio quality will be, and the bigger the file size will be, vice versa. With 8192kbps, the 256GB sd card can record 72.8h and with 1024kbps, it can record up to 582h.

2. What's the read/write speed?

The specified read & write speeds (up to 100MB/s) are based on internal tests. Actual speeds may vary depending on the host device and environment. For devices that do not support UHS-1, the transfer speed will vary due to interface limitations.