Picamera2 performance

[dgalland]

I am looking to measure the throughput of picamera2 in the following configuration:

• RPI4 8GB Full resolution 4056x3040 Two libcamera buffers RGB888

I get the following results:
- request.get_metadata only 10fps (we can't do better)
- request.make_buffer("main") 6.2 fps
- request.make_array("main") 4.7 fps

If I understand:
make_buffer copies the libcamera buffer into a 1D array
make_array creates a 2D array from the 1D array in this case with an extra copy because stride != width*3
I also understand that the size of the RGB88 buffer is 37Mbytes

But I'm still surprised by the copy time, is this normal and can we optimize?

[dgalland]

I took these measurements again with a RPI5, unsurprisingly it is considerably faster.
It appears that the PI5 can easily support any sort of processing of the 10fps received from the libcamera request loop.
On the other hand, I am surprised because the fps of the libcamera request loop remains at 10fps ?
I thought there were also improvements for IO throughput?