C# and VB.Net are both compiled by IL. Also C++ and F# are compiled by it. In fact, the four languages I mentioned are executed at the same speed. There isn't in these "a faster language": the unique difference is between auto garbage-collected languages (C#, VB.Net, F# etc.) and those aren't auto-collected (such as C++). This second group generally is slower, because rarely the developer know how and when collect the garbage in the heap memory, however, if you are informed about the heap memory, the program could result faster if in C++. Hard graphics programs are usually made in C++ (such as the most of Adobe programs). You can also manually collect the garbage in C# (System.GC.Collect();) and in VB.Net (System.GC.Collect).
I know this answer is not fully inherent to the question, but I want to offer you many ways and choices. You choose the right way for your programs.
