Exchange 2007 SP1 Hub throughput with different message sizes

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 […]

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:

25KB
1MB
5MB
10MB

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.
Test Platform and Server Configuration

Hub Hardware: 2 processors x 2 core, 2.2 GHz, 800 MHz FSB, 1MB L2 cache per core, 4 GB RAM, 400 MHz memory, Ultra 3 SCSI disk controller ("entry level") with 128 MB Write-Back Cache, 3 x Ultra320 Universal SCSI 15K RPM disk.

Optimized E2K7 transport database queue configuration:

1 disk for DB logs,
1 disk for DB queue file,
1 disk for OS and other transport logs: Message Tracking, Connectivity, Agent logs, etc.

Transport dumpster is not being used in this environment: 1 Hub and 1 Mailbox without replication.

Mailbox Hardware: A "good" Mailbox server with enough CPU cycles and storage bandwidth to accept message delivery without slowing down the Hub.

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