The Pixels Rendered metric represents the number of pixels that passed the depth-test (both Z-buffer and Stencil if enabled). If the depth-test was disabled, Pixels Rendered counts all the pixels that passed through from the previous pipeline stage.
Pixels that passed the depth-test might not necessarily appear in the render target, which could occur if the color buffer write mask is set to 0.
- If you render a quad with 8x8 pixels, located entirely within the viewing frustum and all the pixels passed depth test, Pixels Rendered is 64.
- If you render a quad with 8x8 pixels, located entirely within the viewing frustum and half of the pixels are rejected by depth tests or other stages of the graphics pipeline, Pixels Rendered is 32.
A high number of rendered pixels results in a high number of pixel shader executions, which requires more rendering time. To keep the number of rendered pixels as low as possible, optimize the rendering order to maximize Early-Z benefit or use a Z-only pass if possible.
To find areas with high depth complexity, use the Overdraw option in the Graphics Frame Analyzer.