1174430 - FPS graph not useful for determining performance headroom / page efficiency

Status: RESOLVED DUPLICATE of bug 1153701

(DevTools :: Performance Tools (Profiler/Timeline), enhancement, P3)

Description

[Dan Callahan [:callahad]]

Attachment: Firefox vs Chrome timelines

See attached screenshot comparing the Firefox and Chrome timelines. Each browser was used to profile slide transitions on:

Top: https://stolksdorf.github.io/Parallaxjs/ (jQuery.animate; lots of painting)
Bottom: http://lab.hakim.se/reveal-js/#/ (CSS3 translations; mostly compositing)

Firefox measures framerate during the profile, which only tells me if my page is efficient enough to hit 60 fps on my specific computer. It doesn't reveal information that lets me understand the margin / headroom I have above that. Thus, I can't easily use the performance tools to continue optimizing my page beyond the point where it hits 60 fps on my development machine.

Chrome measures rendering time per frame, and shows a bar chart growing upwards towards 16.67 ms (60 fps) and 33.33 ms (30 fps). This lets me see the difference between frames that render in 15 ms and ones that only take 2 fps. In Firefox, these are indistinguishable.

Comment 1

[Jeff Griffiths (:canuckistani) (:⚡︎)]

Jordan, some useful feedback here.

Comment 2

[Jordan Santell [:jsantell] [@jsantell]]

We have a few bugs open for frame information that this is dependent on -- victor's working on exposing more information on frames which will get us closer to this goal

Comment 3

[Victor Porof [:vporof][:vp]]

Triaging. Filter on ADRENOCORTICOTROPIC (yes).