I have a 8 gb Pi 4 with a 32 gb SD card. Just taken 15 darks and watched the CPU and memory usage. When downloading images and updating the fits viewer the CPU peaks around 70% and memory usage peaks at about 1.2 gb or around 2.2gb including cache memory. The mount and dome were not being used so need to look again when next observing. No crash to report which is encouraging.