PerfView is often the "tool of last resort" for issues that standard profilers might miss. It excels in:
At least 2GB of RAM is required, though 8GB+ is recommended for analyzing large memory dumps. Quick Start: Collecting Your First Trace PerfView is a CPU and memory performance-analysis tool
It is essentially a wrapper for Event Tracing for Windows (ETW), allowing it to see system-wide events. System Requirements
Because it is a "copy-and-run" executable, you can place it on a production server, collect data, and then delete it without leaving a footprint or modifying the registry.