Sometimes I get questions about how much time it takes to crawl a document. Joel posted an article about the crawl time factors in SharePoint, which can help you estimate this.
"So in a nutshell what are some broad estimates?
- If it’s 10s to hundreds of MBs – measure it in minutes
- If it’s 10s to hundreds of GBs – measure it in hours
- If it’s 1-10TB+ - measure it in days to a week
- 10-100TB – measure it in weeks"
Interesting figures especially when you want to set op the indexing schedules.