We have a time to live collection that is storing log data. We are inputting lots of data all the time. We have indexes on all the columns. In general all querying and inserting is very slow.

I created a test database to look into this in more detail. It has 4 columns including a date field with a TTL index set to 10 minutes. I set profiling on and added MMS

https://mms.10gen.com/host/detail/6bf3ac009f2f321516e6e03349fdca19

Account = iQmetrix
Host = User-PC:27017

I then created a program to insert data as fast as it could, setting safemode=false. This program averages inserting about 600 records per second and queries on indexed fields often take over 30 seconds.

Without TTL and only the _id index I can insert at about 33,000 per second.