ILMerge and peformance with a lot of dlls

Question

I have an application that has over 100 dlls (projects).

I am considering using ILMerge to get that down to about 15 (some cannot be merged because we use PRISM and it looks for the file).

However, doing this merging is a fair amount of work. WPF does not like to be ILMerged and renaming things to make it work is hard (but doable).

My question is, will merging these DLLs together have an affect on performance for my app? or is having the dlls in separate files just as good.

NOTE: By performance, I mean in app performance, not start up time. This is an app that gets started up and then used for a users whole shift (many hours) before it shuts down.

Answer 1

NOTE: By performance, I mean in app performance, not start up time. This is an app that gets started up and then used for a users whole shift (many hours) before it shuts down.

No. Once the assemblies are loaded, the fact that they are in multiple or a single assembly won't matter. The main improvement merging assemblies makes is in load times, not runtime performance.

Merging the assemblies will not help the performance once the assemblies have been loaded.