Open Bug 1696435 Opened 5 years ago Updated 21 days ago

Scrolling with touchpad is very laggy compared to scrolling with a scroll wheel

Categories

(Core :: Panning and Zooming, defect, P3)

Product:
Core
Component:
Panning and Zooming
Version:
Firefox 86
Type:
defect

Tracking

()

Status:
UNCONFIRMED

People

(Reporter: Hondo_McEwen, Unassigned, NeedInfo)

Details

Attachments

(4 files)

My about:support
30.71 KB, text/plain
Details
My about:support
30.71 KB, text/plain
Details
My about support
30.52 KB, text/plain
Details
The code I used
1.77 KB, text/plain
Details

User Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:86.0) Gecko/20100101 Firefox/86.0

Steps to reproduce:

I used my laptop"s touchpad to scroll down a website.

Actual results:

It was very laggy and choppy.

Expected results:

Scrolling with my touchpad should be as smooth as scrolling with my scroll wheel.

The Bugbug bot thinks this bug should belong to the 'Core::Panning and Zooming' component, and is moving the bug to that component. Please revert this change in case you think the bot is wrong.

Component: Untriaged → Panning and Zooming
Product: Firefox → Core

Can you upload your about:support?

Was touchpad scroll always choppy or did it get worse recently?

What website are you scrolling? Even if it's most or many websites please include at least one example site where you see the problem.

Can you upload a profile of the problem using https://profiler.firefox.com/ ? Please use the firefox graphics preset.

Flags: needinfo?(wonghonwen)
Attached file My about:support —
Attached file My about:support —

The touchpad scroll was always choppy and has a low frame rate.I have this issue in google hangouts when I scroll through my chats to see previous messages sent by my friends and the online pdf viewer.

Flags: needinfo?(wonghonwen)

Sorry for the duplicated about:support

Thanks.

Is there a reason that you have set pref layers.acceleration.disabled in about:config to true? Can you try with that pref set to false (after restarting firefox)?

Flags: needinfo?(wonghonwen)

I tried to disable it but I still have laggy scrolling

Flags: needinfo?(wonghonwen)

Can you post your about support now that you have set layers.acceleration.disabled to false?

Flags: needinfo?(wonghonwen)
Attached file My about support —

Thanks. Can you upload a short profile of when you see the laggy scrolling using https://profiler.firefox.com/ ?

OK.I already uploaded. https://share.firefox.dev/3eedeqK

(In reply to Hon Wen from comment #12)

OK.I already uploaded. https://share.firefox.dev/3eedeqK

That's a profile taken while you are scrolling with the touchpad and it is laggy? I don't see any scrolling in there.

Ok.This is my profile with the laggy touchpad https://share.firefox.dev/38rctXI

I uploaded the wrong one. This is the one with my touchpad. Webpage lags before it comes to a stop. https://share.firefox.dev/3kZp6hv

What page were you scrolling?
Did you perform one continuous scroll or did you perform several smaller scrolls so that the page stops moving in between?

Severity: -- → S3
Type: enhancement → defect
Priority: -- → P3
Summary: Scrolling with touchpad ad is very laggy compared to scrolling with a scroll wheel → Scrolling with touchpad is very laggy compared to scrolling with a scroll wheel

I've also observed this on a 2x HiDPI (4K) display with 8th-gen Intel® UHD Graphics 620 (KBL GT2) on Wayland, on Fedora 41 / GNOME 47, particularly on the touchpad; strangely enough, scrolling using the laptop's touchscreen is visibly less janky (although still not perfect) than the touchpad.

I am guessing that the issue is much more noticeable on 4K displays than on regular HD displays. Is this the right issue for this, or this would require a separate ticket?

(In reply to Jeff Fortin from comment #18)

I've also observed this on a 2x HiDPI (4K) display with 8th-gen Intel® UHD Graphics 620 (KBL GT2) on Wayland, on Fedora 41 / GNOME 47, particularly on the touchpad; strangely enough, scrolling using the laptop's touchscreen is visibly less janky (although still not perfect) than the touchpad.

I am guessing that the issue is much more noticeable on 4K displays than on regular HD displays. Is this the right issue for this, or this would require a separate ticket?

I think there are enough differences between the touchpad handling code on Windows (the platform used by this bug's reporter) and Linux, that a separate ticket would make sense.

Attached file The code I used —

Hello Firefox Dev Team,

I was in middle school when I first opened this bug, and it honestly wasn't well written by me. My apologies for that.

I have now revisited this bug and believe a better job can be done explaining my situation. When using a touch pad, there is greater inertial scrolling - it takes a longer time for pages to "glide" to a stop upon release of finger on touch pad as compared to a normal scroll wheel on a mouse (without having an infinite scroll wheel).

As such, when the pages are gliding to a stop, the scroll events increases greatly to ~50 per second as opposed to ~10 when scrolling is at maximum velocity. This is where my issues comes in. Such a high value of scroll events causes my CPU to spike to around 80% within a short time frame, causing frame rendering issues on my device. The "gliding" motion of a webpage coming to a stop becomes janky.

From my understanding, this issue is likely could be caused by a weak CPU and potentially a Firefox specific bug as this CPU spike is not as great in chrome (CPU only hits around 40%). On the other hand, on a more powerful linux machine, I am able to handle ~90 scroll events per second without any lag during "gliding", in Firefox.

The code which I have used to test this is cowritten by me with AI, as seen above.

(Clearing severity to get this bug back into the triage queue given the new information.)

Severity: S3 → --
Attachment #9591947 - Attachment mime type: text/plain → text/html
Attachment #9591947 - Attachment mime type: text/html → text/plain

Hon, thanks for the code.

Indeed I can see very high numbers of wheel events with touchpad scrolling. That's said, I do also see them on Chrome as well, so the underlying problem might not be directly related to the number of wheel events.

The severity field is not set for this bug.
:botond, could you have a look please?

For more information, please visit BugBot documentation.

Flags: needinfo?(botond)

Hello Firefox Developers,

I will attempt to further isolate the issue soon. Would it be better if I add my findings to this thread, or create a new post entirely?

(In reply to Hon Wen from comment #25)

I will attempt to further isolate the issue soon. Would it be better if I add my findings to this thread, or create a new post entirely?

Thanks! Adding findings to this thread is fine.

Flags: needinfo?(botond)

The severity field is not set for this bug.
:botond, could you have a look please?

For more information, please visit BugBot documentation.

Flags: needinfo?(botond)
You need to log in before you can comment on or make changes to this bug.

Attachment

General

Creator:
Created:
Updated:
Size: