Both component can run next to each other on a raspberry pi or similiar device.
There is a project on github that can help with setting up a raspberry pi with docspell.
The REST server component runs very well on the Raspberry Pi and similiar devices. It doesn't require much resources, because the heavy work is done by the joex components.
Running the joex component on the Raspberry Pi is possible, but will
result in long processing times for OCR and text analysis. The board
should provide 4G of RAM (like the current RPi4), especially if also a
database and solr are running next to it. The memory required by joex
depends on the config and document language. Please pick a value that
suits your setup from here.
For boards like the RPi, it might be necessary to use
nlp.mode=basic, rather than
nlp.mode=full. You should also set the
joex pool size to 1.
An example: on this UP board with an Intel Atom x5-Z8350 CPU (@1.44Ghz) and 4G RAM, a scanned (300dpi, in German) pdf file with 6 pages took 3:20 min to process. This board also runs the SOLR and a postgresql database.
The same file was processed in 55s on a qemu virtual machine on my i7 notebook, using 1 CPU and 4G RAM (and identical config for joex). The virtual machine only had to host docspell (joex and restserver, but the restserver is very lightweight).
The learning task for text classification can also use high amount of memory, but this depends on the amount of data you have in docspell. If you encounter problems here, you can set the maximum amount of items to consider in the collective settings page.