New maximum database cache size guidance for Exchange 2007 Hub Transport Server role
Exchange 2007 SP1 has a default transport database cache size of 128MB. This size doesn’t allow as much dynamic growth as may be necessary on Hub servers with higher than normal message rates, or when an unexpected load from increased message size comes into a server. To better allow for cache growth, the new guidance is to increase the DatabaseMaxCacheSize value from 128MB to 512MB on Hub servers with 4 GB or more memory installed.
Read more at source: http://msexchangeteam.com/archive/2008/05/14/448890.aspx
