in reply to Much slower execution from one machine to another
(Have you done a comparison test of old machine mysql vs. new machine MariaDB using the "native" query utilities -- i.e. not via DBI?)
I don't know what to say about the dBase file performance differences; if you've done the same benchmarks on the old and new machines, and the difference in run time is comparable to the difference in percentage spent in IO::Handle::CORE::read, then I would guess that the new system is somehow "not playing nice" with dBase data (or vice-versa) -- something like disk block size (i.e. how much data is physically fetched from the media on a single minimal read) could slow things down under some circumstances if it varies in some silly way from the previous setup.