So you mean i have no problems using 16 8mp on 1 NVR? the only problem i will face is there might be problems displaying all 16 channels on the monitor? So the recording is fine?
Incoming bandwidth is the number to note.
Usually a 4MP camera in H.264 takes about 10mb/s.
ALL cameras must be under the bandwidth limit.
There is also usually a maximum single channel resolution, like my NVR at 24MP for a single camera.
When an NVR displays over 4 channels, it shows the sub stream.
Each IP cameras has at least
two video streams; the full resolution
main stream and
sub stream in standard definition (usually around 720P).
The NVR will always record the main stream.
The NVR switches to showing sub stream per camera to save on processing many video channels at once for multi view.
It makes sense to show a lower resolution video.
Let's imagine you have a 4K monitor connected.
4 channels displayed at once is 1080P effective resolution per per channel shown.
Divided again for 16 channels shown at once is 960x530 effective resolution per channel shown.
Regarding bandwidth, it seems that sub stream contributes to the camera's total bandwidth.
You can turn off sub stream, but then the monitor view will turn black when viewing more than 4chs.
Sub stream is also used for the AI analytics.
If you plan to have some cameras on motion/AI recording only, recording sub stream constantly at least gives some video before it detected and started recording the full 8MP video.
*Recording at full resolution constantly is preferred so nothing is missed and use AI detection to flag when something happened.