x86 version starts faster than x64/Any CPU

Question

Some time ago I noticed that my release version of my application starts 2 times slower than the debug version (10-12 seconds for release and 4-5 for debug). That was becaus

Answer 1

.NET has currently (pre-4.6) different JIT engines for x86 and x64 platforms and they have different startup times. In 4.6 the engines will be more similar and the startup time should be less different.

You can already test with 4.6 pre-version if this is the cause.

Some discussion about this also at https://stackoverflow.com/a/29595194/1806780