a 10 active user Synapse should use about 1GB max, so unsure what’s up with the earlier post. The reason it’s currently so much heavier than XMPP is that resource usage scales with the size of rooms being participated in, not the number of connected users - and we aggressively cache those rooms in RAM. However, 100MB is a much more sensible target and we’re busy optimising to try to shrink things down.