This setting located in /Performance_p.html-page for example gives the java runtime more memory. Same page also has other settings related to ram, such as setting how much memory Yacy must leave unused for the system. (These settings exist so people who run Yacy on their personal machines can have guaranteed resources for more important stuff) Image Other things that would reduce memory usage is to limit the concurrency of the crawler for example. There’s quite a lot of tunable settings that can affect memory usage. Would recommend trying to hit up one of the Yacy forums is also good place to ask questions. The Matrix channel (and IRC) are a bit dead, but there are couple of people including myself there! Also, theres new docs written by the community, they might help as well! yacy.net/docs/ yacy.net/operation/performance/