I wrote, in response to Sven on apparently interminable printing: Aha, I've found the performance bottleneck on this point. I had thought it was GTK, but in fact it was a gross inefficiency in gretl's handling of printing to an in-memory buffer. Printing of large chunks of data in the GUI should now be very much faster. (It's more or less instantaneous for the 250 x 550 dataset.) Allin.