Large message size: effect of transport database cache size on throughput.
Recently one of our support engineers came to us requesting performance data for a client deploying Exchange 2007 SP1 (E2K7 from now on).
The client wanted to know what level of steady state throughput was achievable by a Hub Transport server receiving 4 widely different average message sizes:
We had some of the data but needed to complete the table, so we employed the test bed used to measure transport performance for E2K7 and E2K7 SP1.
Read more at source: http://msexchangeteam.com/archive/2008/05/16/448901.aspx