Performance in Development vs. Live

Hi, we are performance testing and load testing our app for an upcoming launch. Is there a difference between the performance in Development vs Live? Can we do our performance testing in development, or should we do it in production in order to get accurate results?

Performance should be better in live for similar DB size.
Live will also get faster overtime because of CDN and search indexing

Thanks - is this confirmed, or do we just have a set of resources that get assigned evenly across environments? Based on my testing it seems that the latter may be the case.