With Exchange Server 2010, Microsoft has again made several changes to the Extensible Storage Engine (ESE) to increase performance and reduce the frequency of reads and writes. We decided to compile a comparison of the differences between Exchange Server 2003, 2007 and 2010 for user profiles, IOPS, etc. This comparison is available at http://www.demartek.com/Demartek_Exchange_2003_2007_2010_I-O_Comparison_Summary.html.Dennis29