While it's possible to upgrade the Synology with unofficial RAM (and plenty of cheaper options out there, see Reddit and other blogs to make sure you're getting one which the Synology won't be picky about) - I specifically didn't want to have to worry about whether any potential future issues with my DS920+ were related to unofficial RAM. If I wanted cheap and DIY I'd have built my own NAS so I figured I may as well keep it simple and buy the RAM which is verified to work.