Are there differences between running .NET app with 3.5 requirement on machine with or without SP1?

Question

I have an application which requires 3.5 (not SP1.) My understanding is that SP1 is an additive service pack. Therefore, installing SP1 on a machine would not affect my application in any way besides performance. As far as I can tell from the sources listed below, SP1 is mostly about new features, and significant performance improvements were limited to WPF and application cold-boot time.

http://en.wikipedia.org/wiki/.NET_Framework
http://www.microsoft.com/net/WhatsNew.aspx
http://msdn.microsoft.com/en-us/magazine/dd569747.aspx
http://weblogs.asp.net/scottgu/archive/2008/05/12/visual-studio-2008-and-net-framework-3-5-service-pack-1-beta.aspx

My question is this: My application does not use WPF and starting up the application is already relatively fast. Could my clients see performance improvements by installing this service pack? Were there significant performance enhancements to anything besides WPF and time taken for a .NET application to load?

Answer 1

Were there significant performance enhancements to anything besides WPF and time taken for a .NET application to load?

Most of the major performance improvements were in the WPF and the web spaces.

On x86, however, there is one improvement that can have a significant impact - methods which take struct arguments were not candidates for inlining until .NET 3.5 sp1. If you are using custom value types, and passing these into methods by value, you may see some performance improvements in those calls after JIT compilation.

Answer 2

I think you should require version of the framework in which your app was developed and tested. I'm not sure if there were any sugnificant performance improvements in the SP1. Anyway I think that you need to check your app in SP1. Just after release of .NET 3.0 I still was developing application for .NET 2.0 while having 3.0 version installed on my machine. I found out that MS haven't increased versions of the several assemblies modified in 3.0 release. I understand why they did this - for compatibility of 2.0 and 3.0, but nobody can be sure that they haven't added issues with such changes.