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Perfomance problem on Windows 2008 R2 64 bit, IIS 7, .NET 3.5

Hi !

When moving .NET application from WIndows 2008 32 bit, IIS 7
to   WIndows 2008 64 bit, IIS 7 monitoring significant performance degradation.
Testing the same hardware, same installed application, same business flow! Performance slower about 20-30% compared 32 bit machine.

Adding several application and environment details:
-Pure .NET 3.5 server side. C# and VB.NET, compiled as "Any CPU" (tested x64 compilation mode - same result)
-Windows 2008 R2 build 7600
-IIS 7 is running as "Classic" mode.
-Computer Dell, RAM 8GB, Intel Xeon CPU 3.20GHz 3.19 GHz (2 processors)

Please advise what can be configured/checked/tested to find out the problem.

Thanks in advance,
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you can use performance counters to find out where your time goeas away... I think there can be cca. infinite reasons... :)
Go through this process.

Work out where teh bottleneck occurs.

Do a timeline of the relevant processes.

A normal workflow is something like this get timings (via wireshark/netmon, logs in IIS, http.sys, databse logs, firewall logs, etc - hell in process onitor if you want to get heavy)

Client sends request to the Web server
Goes through the networking to get to webserver
webserver receives the request
webserver does stuff (server side code, etc) (talks to db, app tier, backend, middleware, etc, etc get timings of each of these)
Webserver sends request to client.

Then compare this timeline of your web services to a 'working' version.

See where the bottleneck occurs.

Focus on that area.

When you get an area post back here and we will help you more. At the moment it is too vague.


his advices help me a lot