I'm not sure where the bottleneck is for running ikiwiki over a site like my blog [Natalian](http://source.natalian-org.branchable.com/?p=source.git;), though I like to think the markdown processing could be speeded up by the support of the C implementation of Markdown called [Sundown](https://github.com/tanoku/sundown).
>> Sundown doesn't appear to have Perl bindings, so the cost of calling a separate process could wipe out some or all of the speed gain. It might be worth looking into Text::Upskirt instead, which uses the Upskirt library which Sundown appears to be derived from.