Exchange Server 2003 Performance Tools


This topic describes the tools that can help you verify the performance of your Microsoft® Exchange Server 2003 environment. Some of these tools are installed with Microsoft Windows® 2000 Server or Windows Server™ 2003, some with Exchange Server 2003, and others can be found at the "Downloads for Exchange 2003" Web site ( The following table lists specific performance-related tools.


Some tools can cause serious, sometimes irreversible, problems if they are used incorrectly. Before you use tools in your production environment, always familiarize yourself with them on test servers first. Be sure to read the documentation associated with any tool, and familiarize yourself with the risks involved.

Exchange Server 2003 performance tools

Tool name Description Run from Install from

Exchange Stress and Performance (ESP) 

Use to test stress and performance.

This tool simulates large numbers of client sessions, by concurrently accessing one or more protocol servers.

Command prompt

2003 version:

2000 version:


Use to test the performance and stability of the disk subsystem.

Command prompt

Load Simulator (LoadSim)

Use as a benchmarking tool to test the response of servers to mail loads.

For setup and installation instructions, see

2003 version:

2000 version:

Network Monitor

Use to diagnose issues with server connectivity.

Start | All Programs Administrative Tools | Network Monitor

Add/Remove Programs | Add/Remove Windows Components

System Monitor (also known as Performance Monitor)

Use for establishing a baseline of performance and for troubleshooting performance issues.

Start | All Programs | Administrative Tools | Performance

Installed during Windows setup.

LoadSim and ESP are helpful when you test systems to ensure the health of the systems before going into production. You can use the other tools to help diagnose bottlenecks in production servers.

Exchange Server Stress and Performance 2003

You can use Exchange Server Stress and Performance (ESP) 2003 to simulate arbitrary several client sessions that are concurrently accessing one or more Exchange 2003 servers.

ESP provides modules that simulate client sessions over the following Internet protocols and APIs:

  • WebDAV (for Microsoft Office Outlook® Web Access)

  • Internet Message Access Protocol version 4rev1 (IMAP4)

  • Lightweight Directory Access Protocol (LDAP)

  • OLE DB

  • Network News Transfer Protocol (NNTP)

  • Post Office Protocol version 3 (POP3)

  • Simple Mail Transfer Protocol (SMTP)

  • Exchange ActiveSync®

  • Outlook Mobile Access

ESP is similar to LoadSim; however, use ESP when you are validating deployments that use mobility features and Internet protocols that LoadSim does not cover.

For more information about ESP, see the documentation that comes with the tool.


Jetstress helps administrators verify the performance and stability of the disk subsystem prior to putting their Exchange server into production.

Jetstress helps verify disk performance by simulating Exchange disk input/output (I/O) load. Jetstress simulates the Exchange database and log file loads produced by a specific number of users. You use System Monitor, Event Viewer, and Exchange Server Database Utilities together with Jetstress to verify that your disk subsystem meets or exceeds the performance criteria you establish.

With Jetstress, you can perform two types of tests:

  • The Jetstress Disk Performance Test runs for two hours. You can verify the performance and sizing of your storage solution.

  • The Jetstress Disk Subsystem Stress Test runs for 24 hours. You can test your server load using a much larger load over a more significant amount of time.

Running both tests is the best way to verify the integrity performance of your disk subsystem. After a successful completion of the Jetstress Disk Performance Test and Jetstress Disk Subsystem Stress Test in a nonproduction environment, you are ready for the next step in your Exchange Server 2003 deployment process. By running the tests, you help ensure that your Exchange Server 2003 disk subsystem is adequately sized (in terms of performance criteria that you establish) for the user count and user profiles you have established.

For more information about Jetstress, see the documentation that comes with the tool.

Load Simulator 2003

Load Simulator 2003 (LoadSim) simulates the performance load of MAPI clients. LoadSim helps you determine if each of your servers can handle the load that you intend for them to carry. Another use for LoadSim is to help you validate your deployment plan.

However, LoadSim does not account for all of the factors involved in sizing servers. LoadSim does not simulate the following factors that can affect your server capacity planning:

  • Incoming unsolicited commercial e-mail (also known as spam) from the Internet

  • Incoming SMTP mail flow from the Internet or other sites within your organization

  • Use of non-MAPI protocols for account access, such as POP3 and IMAP4

  • Use of mobile devices

  • Public folder usage

In addition, LoadSim does not give a complete picture with regards to user experience, and its results should not be interpreted in that aspect.

For more information about LoadSim 2003, see the documentation that comes with the tool.

Network Monitor

With Network Monitor, you can detect and troubleshoot problems on LANs. Using Network Monitor, you can:

  • Identify network traffic patterns and network problems. For example, you can locate client-to-server connection problems, find a computer that makes a disproportionate number of work requests, and identify unauthorized users on your network.

  • Capture frames (packets) directly from the network.

  • Display, filter, save, and print the captured frames.

For more information about Network Monitor, see the following Microsoft Knowledge Base articles:

System Monitor

System Monitor is a Microsoft Management Console (MMC) snap-in. You can use it to monitor a wide range of subsystems and software. It provides a common infrastructure for reporting data based upon performance counters. These counters are organized hierarchically by object, counter, and (optionally) instance, as follows:

  • Performance Object   The part of the computer you can monitor. Some of the most commonly used objects are Processor, Memory, and PhysicalDisk. When you install Exchange Server 2003, new objects, such as the Microsoft Exchange Information Store (MSExchangeIS), are added to the performance object list.

  • Counters   The parts of the object you can monitor. For example, you can monitor the available bytes, kilobytes, and megabytes of memory in addition to the page faults per second or total pages per second for a Memory object.

  • Instances (optional)   Multiple objects or counters to monitor on the computer. For example, when you look at counters under the Processor object on a multiple processor computer, you see as many instances as there are processors on that computer. You can choose to monitor only a specific processor or all processors.

For more information about System Monitor, see the Windows Help.