@Seungjae-Baek , the resolution of the camera should depend on the use case. However, it is also important to keep in mind what exactly you are doing with the images coming from the hires cameras. For example, if you set the resolution to 4K and you try to view those uncompressed images using voxl-portal, this process will be very taxing on the CPU for the following reason: when you view uncompressed images in voxl-portal, these images are encoded with a software JPG encoder and then sent from voxl2 to your browser. This process is very cpu-heavy. On the contrary, if you use h264 / h265 stream, it should be perfectly fine to encode 4K30 video to disk or even stream, since H264 / H265 encoding is done by a hardware encoder.
voxl-portal, actually does support showing h264 (but not h265) 30FPS streams, so that would be a lot more efficient for the CPU, since there would be no jpg encoding. Otherwise, if you are using raw frames (not _encoded) in voxl-portal , please keep in mind that you will always have a lot of cpu overhead. voxl-portal is designed for debugging / development purposes, so it's not necessarily the most efficient solution for video streaming. For real video streaming use cases, you would use h264 or h265 encoding and save to disk on voxl2 + stream the encoded video for remote viewing. You could encode the same camera source with two different resolutions / codecs / bitrates.
If you need help setting up a specific use case, please provide some details and I can help you further.
Alex