Visualization in general – and OpenDX is no exception – loves memory (RAM). If you find yourself getting "out of memory" errors frequently, you may need to increase your user limits (I would suggest max'ing them out if that is acceptable to your sysadm), or acquiring more RAM. You should also set swap space to 2-3 times RAM for most Unix systems to run DX effectively. Check the $DXROOT/docs/README for your platform for other tips. Then go buy more RAM . . .