How to digest "Shaded Pixels Per Frame" in PVRTune

1

hi guys
i dont think i could understand and make some meaning out of the “Shaded Pixels Per Frame” in PVRTune.
wel, as the name infered, its supposed to be a count of all the pixels that were processed by the shader unit in a frame. should be simple as that.
but, in the real data test, the number just dont add up. namely when looking at this with “Overdraw” counter, and you instantly know the “Shaded Pixels Per Frame” cant be right.

to test this, i built a simple unity app, where i could increamentally increase a full screen overdraw at click. and 10 full screen overdraw at max

and did a section capture in PVRtune

note: on the most left side, no full screen overdraw active; on the most right side, 10xfull screen overdraw active.
the overdraw counter seems to be averaged when overlook the whole capture section.

here is zoomed in a full frame where at the moment a single cube was drawn, and no full screen overdraw ative.
“Overdraw” counter 0.581, “Shaded Pixels Per Frame” = 9.53 million ???

here is a frame from where 10 x Full Screen overdraw were active.
again, “Overdraw” Counter seems to be right, but the “Shaded Pixels Per Frame” = 44.5 million ???

i mean how do you make out of that many pixels per FRAME ?
btw, the test app was run on RedMi9A, with 1600*720 resolution.

clearly, 1600 x 720 x “Overdraw” != “Shaded Pixels Per Frame”

question : how should i digest this “Shaded Pixels Per Frame” ?

2

Hi,
Thanks for bringing up your issue. Could you provide me with:

  • Version of PVRTune that you are using
  • The capture file that screenshots from you are sharing?
  • Binaries of you app you did test with (In case of android it is just .apk file)
  • The ddk version, and android / linux version

How are you increasing overdraw in your app?

3

thx 4 reply, how may i sent you the files, the upload here is max at 8mb

4

You can upload files to Google Drive, and share link either here, or send it to email: devtech.portal@imgtec.com

5

email sent, plz check

6

Thanks for sending files. I recived them and will look at them.

7

I did some tests, and this counter values indeed seem high. I will ask another team how this values are calculated, and get back to you when I know something more about this.

8

Hello,

I confirmed with tools team, this counter is not showing accurate values in this case. What is happening here, is that all calls are marked as frame 0 by process, that is why values are incorrect on graph view. We are currently working on the solution, as this counter does not work well with graph view due to this issue.

Meanwhile, we have another version of PVRTune with access to more direct information from GPU. If you are interested, you can request this version of software from us. You will be required to sign NDA before using it.

9

cheers, mate. any idea when will a fix be pushed publicly available yet

10

It will be available soon, we will let you know once the fix is up.

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