The

1x1 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

Show Wireframe

override mode to check whether the geometry is complex. If the geometry is not complex, then the vertex shader is the bottleneck.

However, the effect of this override mode is driver/graphics hardware vendor specific and depends upon whether scissoring on your device occurs prior to or after the pixel shader stage.