Just thought I'd share the results of a test of the IMS Enterprise enrolment plugin, because the results are quite nice. Finally getting round to testing with university-size data files.
This test was specifically about creating user accounts (which the plugin can be configured to do) rather than the enrolments - will test it with enrolments later.
System: Apache 1 on AIX, PHP 4.3.8 (installed as a CGI), MySQL 5.0.18
Data file: 33.81MB, 13960 <person> records, 3914 <group> records, 100801 <member> records
Starting with a Moodle with no accounts registered (except for the standard ones you have to have, and a couple of extra admin ones).
First run: Created over 13,800 user accounts. (Some of the records in the file have missing data so can't be added.) Time taken: 521 seconds.
Second run: Created no new accounts - accounts already existed from first run. Ensured all accounts were active (not flagged as "deleted"). Time taken: 366 seconds.
I think that's a pretty good result: less than ten minutes to add a whole undergraduate population to Moodle, from scratch!