[blink-dev] PSA: a new fps meter

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Xida Chen

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Jul 2, 2020, 5:16:57 PM7/2/20
to blink-dev

Hi all,


I am very pleased to announce that the fps meter now has a new name and a new look! Here’s a screenshot and summary:



Here are the key differences:

  • Showing percentage (of frames that were successfully rendered) better reflects the smoothness of the page. The fps meter would show a count of frames rendered, meaning that inactive or idle pages showed lower “fps”, even if they hit every frame.The new meter only tracks dropped frames if the page had new content to present but didn’t present on time.

    • For example this demo has a main-thread animation lasting for 1 second and only the first half has visual updates. The fps meter shows 30 fps. It’s confusing because the demo is perfectly smooth, able to render every frame on time. The “Frame Rendering Stats” shows 99% which indicates that virtually no frames are dropped. Note that we often show numbers less than 100% because one of the expected frames hasn’t finished rendering yet.

  • The “Frame Rendering Stats” provides more immediate information. Using green/red/yellow lines for each individual frame rather than showing an aggregation of smoothness over time. For example, when navigating from one page to another page, we can see a bunch of red lines. These are frames being dropped due to page load. With this, it’s possible to tell which portions of the page experience aren’t smooth.


The name FPS meter has become a little dated, as it no longer measures FPS, nor is it a meter, and it shows other stats like GPU raster and GPU memory. We’ve decided to update the name to “Frame Rendering Stats” to cover the new and existing details surfaced.



Sean Morris

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Feb 16, 2021, 4:10:05 PMFeb 16
to blink-dev, Xida Chen
It shows everything but FPS. Outstanding.

Michal Mocny

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Feb 16, 2021, 5:23:07 PMFeb 16
to Sean Morris, blink-dev, Xida Chen
I laughed :)

Naming awkwardness aside, this new meter is expected to produce a more representative metric.  Do you have concerns with the new approach or poking some good fun at its naming? (Which btw, is why we’ve decided to update the name to “Frame Rendering Stats”).

2 key takeaways with this change are:
  • "The new meter only tracks dropped frames if the page had new content to present but didn’t present on time."  I expect this is a positive change.
  • The change from fps to %age.  If you assume a fixed frame rate, the conversion should be easy.  I can see why you may dislike this change... however, percentage does better to ignore different & variable refresh rates.  You immediately notice rendering issues without needing to think about those factors alongside.
-Michal

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Xida Chen

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Feb 16, 2021, 7:44:28 PMFeb 16
to Sean Morris, blink-dev
Hi,

Thanks for your feedback.

My original email already outlined the benefits of the "Frame Rendering Stats" over the old "FPS meter", so I won't iterate over them again.

We did hear from our users and developers that they want the fps meter back, we are working on it to accommodate their feedback. This is tracked at crbug.com/1124189, please do feel free to add your comments there so that we can keep them tracked.

Xida Chen

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Feb 23, 2021, 9:21:31 AMFeb 23
to Fawad Tariq, blink-dev, Sean Morris
Thank you for your feedback.

Please try this on Chrome canary: https://www.google.com/intl/en_ca/chrome/canary/

On Tue, Feb 23, 2021 at 9:09 AM Fawad Tariq <fawad...@gmail.com> wrote:
What are we supposed to do with all this information? We get everything except the actual FPS, which is almost all we need. Cheers to Google Chrome team wasting their time, money and effort in not giving us what we want.

I agree with Michal Mocny about this being a positive change, but keeping the FPS in its place wouldn't hurt anybody.

Mathias Bynens

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Feb 23, 2021, 9:36:13 AMFeb 23
to Xida Chen, blink-dev
Nice work!

One question: this seems to undo the earlier work to make the color scheme used by the Frame Rendering Stats tool color-vision-deficiency-friendly. Are there any plans to restore the more accessible colors in the new version?

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Xida Chen

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Feb 23, 2021, 9:55:06 AMFeb 23
to Mathias Bynens, blink-dev
Hi Mathias,

I don't think we changed the color theme. Please see a screenshot here: https://drive.google.com/file/d/1_4LyH4s-1p-wSljC3Qnuq6Qmn7_omAdY/view

To be more specific, the colors for "dropped frame", "partial frame" and "successfully rendered frame" don't change at all.

I hope that answers your question.

Mathias Bynens

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Feb 23, 2021, 10:02:17 AMFeb 23
to Xida Chen, blink-dev
Yes, it does. Thanks!

Fawad Tariq

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Feb 23, 2021, 1:49:08 PMFeb 23
to blink-dev, Xida Chen, blink-dev, Sean Morris
What are we supposed to do with all this information? We get everything except the actual FPS, which is almost all we need. Cheers to Google Chrome team wasting their time, money and effort in not giving us what we want.

I agree with Michal Mocny about this being a positive change, but keeping the FPS in its place wouldn't hurt anybody.

On Wednesday, February 17, 2021 at 5:44:28 AM UTC+5 Xida Chen wrote:

Dirk Pranke

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Feb 23, 2021, 2:41:27 PMFeb 23
to blink-dev
Hi all,

A friendly reminder from one of your community@ managers ... 

Please remember that we're assuming that everyone is trying their best here to improve Chromium and that sarcasm, while very tempting as a way of communicating your feedback, can often be misconstrued and is rarely very helpful. Nor is claiming that someone is "wasting their time".

Trying to be direct, clear (and kind!) instead usually works better, so please try to do that instead where you can :)

Thanks,

-- Dirk

-- Dirk

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