There is a report you can run (do you have reporting installed?) that will show the performance log.  That will show times for the steps during collect and publish.   The times you mention don't surprise me for a IaaS backend.  This software is VERY dependent on DB performance, and the install guide does recommend ensuring your DB is as close as possible network-wise from the app server(s).   

May I ask why you are collecting groups on the Identity collector?  When you pull in groups that way, they do not represent permissions, they are not reviewable.  I call these "IG Groups" and they are used to assign permissions IN IG, and as criteria in search parameters in reviews (that is, you can run a review for users in a group, if you want)   But you still would need to collect all those groups in an application data source in order to review them.   In my mind those IG Groups are limited in functionality, and unless you've got a good use for them, I'd suggest not collecting them on the Identity collector.

--Jim