How to improve MongoDB insert performance

Question

The result:

If you are operating on a dataset that is fault tolerant, or doing a one time process you can verify, changing WriteAcknowledge

Answer 1

"There is not a substantial read rate on the database so Sharding would not improve matters, although perhaps I am wrong."

An update involves a read. aka finding that forsaken _id -- so perhaps sharding might be helpful if not v helpful