Didier Verna <verna(a)inf.enst.fr&gt; writes in xemacs-beta(a)xemacs.org: Nobody has run any benchmarks, other than Hrvoje who has demonstrated that it is faster to start with autoloads dumped instead of loaded at start up. For 21.0 we're leaning towards the more flexible side at the cost of slower startup. If you are building from source, you can dump anything you want. My guess is that as computer speeds increase, the greater flexibility of minimal dumping outweighs the hardcoding of dumping. I am hoping the redesigned non-dump in 21.2 makes this pretty much a moot point.