With dual core processors coming out, I was thinking about about whether listserv is multi-threaded or not and could take advantage of them, or hyperthreading, or a multi-processor. Most of the time it's not an issue, but some commands do knot it down pretty well for "awhile" (Pentium 1 G, 1G of memory, I think, 1900 lists). And, yes, I know about the hpo option, which would speed up some commands but I don't think it's the same. (Unless I've missed it, and my archive search is bad, we haven't discussed this for awhile. If we have, my apologies)