Analyzing Time for Individual Ergs and a Group of Ergs with Graphics Frame Analyzer for DirectX*

Graphics Frame Analyzer for DirectX* gives you the ability to analyze both the time for individual ergs and the time for a group of ergs submitted to the hardware together to better represent a pipelined workload.

To compute an individual erg time, the Graphics Frame Analyzer for DirectX* brackets each erg with timing markers, while groups (such as render target regions) are calculated as a single unit so the hardware utilization more closely resembles the expected workload. Therefore, it is rare for the sum of the individual erg timings to match the total region time. Examining a frame you should use:

But optimizing a single erg may have less of an effect on the whole frame than indicated because the pipeline may be hiding latency caused by that particular call.

 

The metric values shown…

Graphics Frame Analyzer for DirectX* calculates the metric values …

Note

Frame Overview Tab

… represent all ergs within the frame, independent of which ergs are selected

… by gathering the metrics from the hardware in a single call for the entire frame

If you select all ergs the metric values displayed in the Details tab are typically larger than shown in the Frame Overview tab, since pipelining benefits are not taken into account.

Details Tab

… represent only the selected ergs

… by summing the metrics values for all selected ergs

Scene Overview Panel

… represent individual ergs (for individual ergs), or the total for that group of ergs (for all groupings of ergs)

… as a single call to the hardware for each entry in the tree

 
 

The following examples demonstrate how the Graphics Frame Analyzer for DirectX* calculates and displays erg metric values.

Analyzing all Ergs in the Frame

Let’s select all ergs in the frame. Values for the GPU Duration metric in the Scene Overview pane (15853.0) closely match those in the Frame Overview tab (15853.0), since both were calculated as a single call to the hardware.

Switch to the Details tab. Note that the GPU Duration metric in the Details tab is far higher (16888.8), since the values in the Details tab are calculated by summing all the values of the individual ergs.

Analyzing a Render Target and all Ergs within It

Now let’s select a single render target and all ergs within that render target. In the Scene Overview pane, note that the values for the entire render target is not the sum of the individual ergs (66 versus 108.3), since the value for the render target was calculated by making a single call for the entire group rather than summing the values for the individual ergs. However, note that the value shown in the Details tab is the sum of the metric values (108.3), since metrics in this pane are calculated by summing the metric values of the ergs that you have selected.