Webserver Stress Tool 

Webserver Stress Tool is a powerful HTTP client/server test application, designed to pinpoint critical performance issues in your web site or web server that may prevent optimal experience for your site's visitors. Supports SSL.
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Video Card Stability Test 

Free Video Card Stress Testing! + Free Benchmark the speed of your 3D graphics video card! + Free 3D Screensaver!
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WinFeedback 

WinFeedback is a Windows scripting extension for testing, monitoring and automation purposes, like response timing, up-timing, functional testing, stress testing, health monitoring, task automation.
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Socket Workbench 

Socket Workbench is the definitive tool for analysing socket communications that underlie the Internet and several types of inter-process communication.
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