The tests are based on a developed website, which is hosted on IIS 7.5. A static html page is under the tests via webbench 1.5.
Webbench simulated 1000 clients, running 300 sec. to access the website. Nginx is used to distribute web reqeusts to 3 servers that host the website.
This time, the tests are all running on the virtual machines. Below are the testing results.
Speed=91117 pages/min, 777535 bytes/sec. => 759KB/sec
Requests: 455587 susceed, 0 failed.
Speed=92961 pages/min, 793268 bytes/sec. => 775KB/sec
Requests: 464806 susceed, 0 failed.
Speed=94324 pages/min, 804899 bytes/sec. => 786KB/sec.
Requests: 471621 susceed, 0 failed.
Based on succeed requests, there is 2.02% and 3.52% increase. It sugggests the more IIS websites added, the more throughput could be produced.