This graph displays the bandwidth the server was able to deliver (as a total) as well as the average bandwidth that was experienced by the simulated users:

In this graph we can see that the average bandwidth available per user goes down from 360 Mbit to 80 Mbit when the number of users climbs from 1 to 100 users.
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.
Welcome
Introduction: Testing Basics
Performance, Load or Stress Testing?
Calculation of Load and Load Pattern
Webserver Stress Tool Features
How much load can Webserver Stress Tool generate?
Installation
Configuring Webserver Stress Tool
Selecting the Test Type and the Number of Users
Selecting the URLs or Editing the URL Script
Using Custom URL Scripts for Advanced URL Sequences
Performance Tips&Tricks
Running the Test
Reviewing Logfile Results
Analyzing Graphical Results
Graph Click Times & Errors (per URL)
Graph Click Times, Hits/s and Clicks/s
Graph Server and User Bandwidth
Creating Reports
Additional Features
Appendix
Software License and Contact Information