If your IIS log files are local then you can log in as the sysadmin, go to Settings and then go to Service Settings. It is not recommended that you make changes in this area.
The way SmarterStats imports data is that it works on sites one at a time (importing) for approximately 15 minutes and then it goes into an idle state. Then, 15 minutes later it continues the process from where it left off.
If you are using FTP to import files then you have control over how often it imports files for particular sites. This setting is in the Manage, Manage Site, Action, Edit Site area.