1×1 Scissor Rect
The 1×1 Scissor Rect override mode cuts pixel processing from a pipeline: if the frame rate does not increase after enabling this override, then a complex geometry or vertex shader is a bottleneck. In this case you can use the Wireframe override mode to check whether the geometry is complex; if it is not, then the vertex shader is the bottleneck.
However, the implementation of this override mode is driver/graphics hardware vendor specific, therefore you should apply scissoring prior to or after the pixel shader stage.
NOTE
On the Intel® GMA 4500/X4500/X4500HD/4500MHD devices, scissoring occurs prior to pixel shader stage, and only one pixel location will have pixel shader activity. This effectively removes all pixel shader compute time, texturing, and pixel fill rate overhead.
See Also
Override Modes Overview
Disable all overrides
Null Hardware
Disable Draw Calls
Wireframe
2×2 Texture
Simple Pixel Shader
Disable Texture Filtering
Disable Z-Test
Disable Z-Write
Cull None
Cull Clockwise
Cull Counter-Clockwise
Disable Alpha Blending
Disable Alpha Test
Overdraw Visualization
FPS Limit