Microsoft effectively reduced the I/O demands Exchange placed on the storage subsystem by making significant improvements to the Store. Using a larger page size of 8K allows more data to be transferred during each I/O operation. Increasing the database cache size allows for greater portions of the user mailbox data to be stored in database cache, which can significantly reduce the I/O to disk. Considering the cost and complexity of Exchange Storage, the benefits of adding memory can become quite apparent. Couple the I/O reduction from increasing memory along with deploying Outlook 2007 client using Cached mode, there is significant reduction in storage performance requirements to deploy an Exchange 2007 server when compared to Exchange 2003 server.

However, there are several other factors to consider when moving to Exchange 2007. It is important to understand that there are non-transactional I/O demands related to database maintenance and backup operations that do not benefit from the added memory. For these non-transactional tasks, you must ensure that maintenance tasks can be completed within the designated maintenance window to ensure the Exchange server's operations run smoothly.