Precompile .NET code into machine code

If you are sure it is the algorithms that are slowing things down (and you would be surprised how often it turns out to be something else entirely) then the best course of action is to recode them into a DLL in a native language, and call that from your C#.

Profile it first, and check that you really know what is taking time. Then focus on that bit.

NGEN is the tool for generating machine code. However, in some cases NGEN can cause code to be less optimized than if you used JIT. Mainly because JIT can take advantage of processor model specific instructions, whereas NGEN creates code for a family of processors. Also, NGEN complicates the deployment process because you have to deploy the NGEN images to a special location instead of just copying your exe's and dll's locally. Most of the benefits of NGEN are in startup time because the JIT penalty for each method only happens once.

The bottom line: Profile your application using JIT and NGEN and see which option is best.

Some useful links:

http://msdn.microsoft.com/en-us/magazine/cc163610.aspx[^]
http://msdn.microsoft.com/en-us/magazine/cc163808.aspx#S2[^]