We did some testing with vTiger crm and have found a configuration that makes it possible to import large files. Wie used a suse linunx machine with vtiger 5.2.1
These are the settings we used:
1) in config.inc.php
memory_limit = 2048 MB
$upload_maxsize = 100000000
2) in php.ini
max_execution_time = 600 seconds
max_input_time = 600 seconds
3) in modules/import/importstep2.php
$_SESSION[‚recordcount‘] = 250
(This imports the files in sets of 250 records, makes a http redirect and loads the next set. You have a kind of progress bar here.)
4) in modules/import/importsave.php
setTimeout(„b()“,10000);
With those settings we where able to import 135.000 records with a filesize of 75 MB. With memory_limit = 512 MB the maximal number of records was 50.000.