How to make MSVC debug builds run faster

Question

We have a large C++ application, which sometimes we need to run as a debug build in order to investigate bugs. The debug build is much much slower than the release build, t

Answer 1

Are you using MFC?

In my experience, the main thing that can make a debug version slow is the class validation routines, which are usually disabled in release. If the data structure is at all tree-like, it can end up re-validating subtrees hundreds of times.

Regardless, if it is, say, 10 times slower than the release build, that means it is spending 1/10 of its time doing what's necessary, and 9/10 doing something else. If, while you're waiting for it, you just hit the "pause" button and look at the call stack, chances are 9/10 that you will see exactly what the problem is.

It's a quick & dirty, but effective way to find performance problems.