# ZM_rpi3_HWACCEL_Testing Testing the hardware video decoding peripheral of the rpi 3 in ZM, with Devuan Stretch and 1.31.44. This incidentally shows how to build ZM from source using the docker script (not recommended but sort of works) The results are that, ZM 1.31.44 has comparable resource usage for a 3.5 FPS 640x480 camera in RTSP and MJPEG mode. They both use about the same amount of CPU. Note that there is a limit on how much mmal HWACCEL you can use, so it may not scale to more than say 3 or 4 cameras (testing soon).