Comment 2 for bug 160717

As far as I can see Azureus respects its heapsize set via -Xmx, setting it to 16MB then trying to open help/about will cause an OutOfMemoryError crash. Note the with Azureus starting a torrent is an extremely lowcost procedure, hence why it doesn't seem to cause a crash.

Note that Azureus also uses directly-allocated memory, which is by default bound to the same size as the heap size. Azureus also by default has a 5MB cache enabled, which uses memory. In addition, SWT widgets and other parts of the GUI might use X11 or system memory not bound by the Java heap. /usr/bin/azureus by default sets the heap to 1024M because small heaps can cause OOM errors on large torrents.

For me, Azureus starts at around 37MB, and in the course of 3 days or so grows to around 60-70MB while doing 4 torrents, which is very respectable memory usage -- it's a bit higher than KTorrent, and honestly about on par with Deluge.

Do you have any 3rd party plugins enabled? If memory usage is increasing over time, try disabling DHT (if that's possible) -- that's the only thing that should be "growing" over time.