Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Incorrect display latency reported. #342

Open
Emjayen opened this issue Aug 14, 2024 · 2 comments
Open

Incorrect display latency reported. #342

Emjayen opened this issue Aug 14, 2024 · 2 comments

Comments

@Emjayen
Copy link

Emjayen commented Aug 14, 2024

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
Copy link
Collaborator

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
Copy link
Collaborator

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.

Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment
Labels
None yet
Projects
None yet
Development

No branches or pull requests

3 participants