I'm aware that ReSharper does have a way of monitoring memory consumption within Visual Studio, and I've been told that the consumption does usually also include memory allocated by NCrunch.

At present there are no known memory leaks caused by NCrunch within the Visual Studio IDE, although naturally NCrunch does need to store a large amount of information (such as code coverage and test results) and it will therefore increase memory consumption in the IDE, particularly when working with very large solutions that contain a lot of code/tests.

Of course, keeping memory usage in check is always a long term goal with any software .. NCrunch isn't perfect, but it progressively improves from version to version :)