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What frame rate settings are available, and where are they documented?

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  • Last reply by MarjaE

MarjaE
MarjaE
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I use layout.frame_rate 1 to block animation, and to replace painful partial scrolling with clean jumps. I can't use an intermediate frame rate, such as 3-30 fps, due to the seizure risks, or a high frame rate, such as 60 fps, due to migraines when hit by "smooth" animation, "ease in-out" animation, zooming animation, parallax animation, partial scrolling with one part of the window sliding alongside another, etc.

about:config involves some other frame-rate and frame_rate settings;

gfx.display.frame-rate-divisor starts at 1

layers.offmainthreadcomposition.frame-rate starts at -1

layout.expose_high_rate_mode_from_refreshdriver starts at true

layout.frame_rate starts at 0, which defaults to monitor settings; I've reset it to 1 (1 frame per second).

layout.throttled_frame_rate starts at 1

What are these and what do they do? I've tried looking them up, and see a bunch of posts about browser diagnostics, or *increasing* frame rates, or the like.

I use layout.frame_rate 1 to block animation, and to replace painful partial scrolling with clean jumps. I can't use an intermediate frame rate, such as 3-30 fps, due to the seizure risks, or a high frame rate, such as 60 fps, due to migraines when hit by "smooth" animation, "ease in-out" animation, zooming animation, parallax animation, partial scrolling with one part of the window sliding alongside another, etc. about:config involves some other frame-rate and frame_rate settings; gfx.display.frame-rate-divisor starts at 1 layers.offmainthreadcomposition.frame-rate starts at -1 layout.expose_high_rate_mode_from_refreshdriver starts at true layout.frame_rate starts at 0, which defaults to monitor settings; I've reset it to 1 (1 frame per second). layout.throttled_frame_rate starts at 1 What are these and what do they do? I've tried looking them up, and see a bunch of posts about browser diagnostics, or *increasing* frame rates, or the like.

Chosen solution

You can possibly search the source code and check comments of a specific pref.

I don't think that anybody of the regular users who answer questions has the knowledge to know what these prefs are about and determine whether it is safe to modify those prefs, so be cautious.

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All Replies (3)

cor-el
cor-el
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  • Top 10 Contributor
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Chosen Solution

You can possibly search the source code and check comments of a specific pref.

I don't think that anybody of the regular users who answer questions has the knowledge to know what these prefs are about and determine whether it is safe to modify those prefs, so be cautious.

cor-el
cor-el
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  • Top 10 Contributor
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You can toggle a pref via the command line in the Browser Console.

Note that the response gets slow if you set the pref to 1. There is set/getIntPref and set/getBoolPref for the Number (Integer) and the Boolean prefs. 

var pref_name="layout.frame_rate";
var fr=[1,-1]; /* -1 is the default (60) */
Services.prefs.setIntPref(pref_name,Services.prefs.getIntPref(pref_name)==fr[0]?fr[1]:fr[0]);
console.log(pref_name,Services.prefs.getIntPref(pref_name));

MarjaE
MarjaE Question owner
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Wow, thank you!