PerfHUD 5.1 Highlights:
- GeForce 8 Series support on Windows Vista and XP (older GPUs are also supported)
- Microsoft Windows Vista support (DirectX 9 and 10)
- New in 5.1! Instrumented driver updated to 163.71
- New in 5.1! Compatibility with Managed and XNA applications
- New in 5.1! Ability to tone map and save out textures and render targets
- New in 5.1! Complete changelist from PerfHUD 5.0 to 5.1 (.txt)
- Interactive usage model
- Shader edit-and-continue
- Render state edit-and-continue
- Revamped customizable user interface
- Automatic bottleneck identification
- Complete PerfHUD 5.1 feature list
http://developer.nvidia.com/object/nvperfhud_home.html#downloads