in reply to Need to process a tab delimted file *FAST*

The module Text::CSV_XS parses records using an XS module, which may be faster than a pure Perl solution. It can handle tab-delimited files as well:
use Text::CSV_XS; $csv = Text::CSV_XS->new( sep_char => "\t"); $columns_ref = $csv->getline($io);

-Mark