System Requirements
of Webserver Stress Tool

Recommended Hardware and Operating Systems

The operating environment is a 32-bit version of Windows Server 2003 R2, Windows Server 2008, Windows Vista, or Windows 7 on a workstation built 2010 or later (at least a 1-2 GHz processor, 1 Gigabyte RAM, and a fast network connection). The target web servers can run on any operating system.


Test Client Details

Please find requirements for operating system, hardware, and network below.

Operating System

Webserver Stress Tool runs on all 32-bit versions of Windows (2003 R2 or later). Depending on your Windows version there are limitations in the number of users you can let run simultaneously. Please prefer older Windows versions for better performance, as outlined in the table below.


Windows Version

Maximum number of users that can be simulated on one machine

Windows Server 2003 R2 32bit

Up to 10,000 simultaneous users


Windows Vista 32bit

Windows 2008 R1 32bit

Windows 7 32bit

Up to 4,000 simultaneous users



Serious testing can be conducted with any better PC built in 2010 or later (at least a 1-2 GHz processor, 1 Gigabyte RAM, and a fast network connection). More CPU power and multithreading or multiprocessing will be helpful for high traffic scenarios (e.g. when several thousand users are simulated). Try to supply 1 GB of RAM, 2 GB should be enough even for high traffic scenarios. Webserver Stress Tool records the CPU load of the client machine during the test, so you can check after a test whether you need more processing power.


For load tests the network connection between the test client and the server is critical. For the connection between the server and the test client you must provide the full total bandwidth that an equal number of real users would use when accessing your server!

Target Webserver Details

Webserver Stress Tool can test all HTTP servers that are accessible via TCP/IP since nothing has to be installed on the webserver and the connections to the server are using standard HTTP protocol. For example you can use it with the following webserver environments:

Windows IIS
Apache on Windows or Linux
Various flavors of Linux


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