16GB Memory for DS918+
https://nascompares.com/guide/synology-ds918-16gb-guide/

Supported memory: DDR3L/LPDDR3 up to 1866 MT/s; LPDDR4 up to 2400 MT/s
https://ark.intel.com/content/www/us/en/ark/products/95594/intel-celeron-processor-j3455-2m-cache-up-to-2-30-ghz.html