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I'm trying to use WCAT to pound my web application and test out the performance. However, I'm not sure I'm testing on the right combination of IIS & OS.


  1. What are the limitations of IIS on different OS? I heard from one source that IIS 5.1 on windows XP can only handle max of 10 concurrent connections, does it even make sense for me to pound it with 1000 concurrent connections?

  2. In a different source, I heard for .NET 2.0, maxium concurrent request per cpu is 12. So I'm a bit confused here. Which one is it? For IIS 5.1 on .NET 2.0, which one is it? 12 or 10?

  3. For IIS 7 running on windows Vista and windows 7, it seems like there is also a maxium request limit but then again, from different source, I heard IIS 7, you can set a maxium request to a huge number like 5000, so again, confused here. Is there a difference between IIS on windows vista/windows 7 and the server editions such as windows server 2008?

Thanks for your suggestion.

share|improve this question
up vote 2 down vote accepted

All of the non-server Windows OSes are limited in the number of concurrent incoming connections they will accept (one of the many things that differentiates Microsoft's desktop OSes from their server OSes). Are you planning on serving your website via a desktop OS while in production? Don't do that, please.

share|improve this answer
Hello Erik, no I'm not. However, as a developer, I do want to test the application locally and use WCAT to pound the application and use performance counters to measure the available CLR threads, Application Queues and etc. – Liming Sep 13 '11 at 3:47
You ought to be doing your testing on the same environment as prod. Doing otherwise will only give you useless and irrelevant test results. – EEAA Sep 13 '11 at 4:55
Potentially worse than useless -- something might seem to work in your "test" environment, but only because of some bit of software you don't even remember installing, leaving you with no clue why it refuses to work on the live environment. – Shadur Sep 13 '11 at 7:01
Thanks guys. I will be installing windows 2008 server, so I can pound it with realistic traffic analysis. Greatly appreciate it. – Liming Sep 13 '11 at 13:49

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