Database creation time with DBI and the SQLite DBD

I have 445, 6 element csv files, about 350000 lines in all. I only have
one machine, but a number of Linux OS.

These csv files are parsed, the data checked for purity and then placed
in an sqlite file.

On one OS, this takes 30-35 minutes, on several other operating systems,
it takes 7-8 hours.

I am at a loss to understand why this is so.

Are there any suggestions as to what may cause this anomaly?

The version of SQLite is 3.6.13 



TIA



Owen