There is a tool built right into HoloLens that does a great job of letting you see how your application is running. It displays SoC (system-on-chip) power, system power, Frame Rate, GPU, CPU, input/output, network, and memory. On most of the HoloLens projects I work with this, as this is the first test to perform when performance is not great.
Let's take a look at System Performance:
This can be accessed from any PC on the same network by pulling up a browser and typing the device's IP address into the browser address bar. This is one of the few debugging and profiling tools that does not seem to affect the performance of the application.