如何在启动时提高被引用dll的加载性能?

I have an windows forms application on .NET 4 framework and using Devexpress components. In first run of my application it wait 20 or 30 seconds for loading assemblies. After that it runs like a rocket :) How can I solve this? I googled some and found NGEN.exe. I don't have any idea NGEN is usable or not. Is there any another simple way for increase load assembly speed? What do you prefer? I have an windows forms application on .NET 4 f