Incorrect display latency reported.

[Emjayen]

PresentMon is reporting seemingly an error of +1 frame for the display latency, as verified against GPUView.

PresentMon trace GPUView ETL System info

[markgalvan-intel]

Hello,

Is there a specific frame that is showing this error? We took a look at the provided ETL file and based on a random selection of frames the calculated display latencies in the generated CSV file matched the manually calculated display latencies. A few of the frames we sampled:

Line 278 Display Latency: 31.966, Manual using GPUView: CPUStart: 63534017, DxgKrnl VsyncDPC: 63853677 = 319,660 Line 622 Display Latency: 32.276, Manual using GPUView: CPUStart: 120837748, DxgKrnl VsyncDPC: 121160517 = 322,769 Line 875 Display Latency: 30.514, Manual using GPUView: CPUStart: 163257217, DxgKrnl VsyncDPC: 163562359 = 305,142

We generated a CSV file from the provided ETL file as the attached CSV does not seem to correspond with the ETL file. Command used to generate the CSV file: PresentMon-2.1.1-x64.exe --process_name dxtest.exe --etl_file "F:\DataAnalysis\External\bad-waitable\merged.etl" --output_file "F:\DataAnalysis\External\bad-waitable\test.csv

[jenatali]

When I looked, it seemed like all frames were submitted, confirmed, and scheduled to flip on the next VSync, all within a single VSync span. Is the monitor running at 30hz? I didn't check that but that could explain it.