dotTrace is Performance and Memory profiler from JetBrains.
dotTrace and ReSharper are tightly integrated. For example, you can profile separate tests in your code base.
dotTrace 4.0 (currently in beta) have a lot new features (you can read about them at EAP page) and fully compatible with coming release of ReSharper 5.0.
But current release of dotTrace 3.1 is not compatible with new version of ReSharper (only in integration part).
ReSharper dotTrace 3.1 Integration PowerToy will allow you to reconcile dotTrace 3.1 and ReSharper 5.0 back together.a simple to use performance and memory profiler by JetBrains. This PowerToys integrates ReSharper 5.0+ and dotTrace 3.1 so developers can profile their unit tests.