Closed Bug 1204335 Opened 9 years ago Closed 6 months ago

FF scrolling performance still not as good as Microsoft Edge Browser


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

40 Branch
Windows 10





(Reporter: David-peters, Unassigned)



(Keywords: perf, Whiteboard: [gfx-noted])

User Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:40.0) Gecko/20100101 Firefox/40.0
Build ID: 20150826023504

Steps to reproduce:

Open any web page with the Microsoft Edge browser on a notebook with two finger scroll touchpad support, preferably with a Synaptics model, preferably with the latest Synaptics drivers (tested with Synaptics driver version v19.0.12.95 on Windows 10 64 bit).


Do the same with Firefox.

Actual results:

MS Edge scrolling is the best scrolling ever experienced on any platform. It is exactly as if the page itself was directly touched with the fingers. Scrolling ballistics are also absolutely perfect.

Firefox scrolling (as compared to the above!) is ridiculously bad.

Expected results:

Firefox scrolling should be at par (or better) with Microsoft's latest scroll technology as can be found in the new Edge browser.
Preferably try the scrolling performance of the Edge browser in the traditionally worst scrolling, heaviest pages like eBay, Amazon, Facebook, you name them.

You've never seen anything like it.
Component: Untriaged → Panning and Zooming
OS: Unspecified → Windows 10
Product: Firefox → Core
Hardware: Unspecified → x86
Please make the test. Use the Edge browser for one hour reading news, visiting your favorite pages, hopping around the web.

Then go back to Firefox.

--> without words. Terribly, terribly bad, feels like going back to like 1989, performance- and scrolling-wise. The Edge Browser truly opens up a new class of its own.

Please act, Mozilla. This is an absolute killer.
(In reply to David.P from comment #2)
> Please act, Mozilla. This is an absolute killer.

It is being worked on but it's not a trivial amount of work. Bug 1013364 tracks all the work that's going into this.
This may be related to the scaling that Windows 10 does on high resolution screen. FF performance on a Dell Latitude E7240 running Win7 even when connected to a QHD screen in native resolution is decent. It is actually usable.

Look at the same page on a brand new Dell XPS13 (2015) with Core i7 but running Win10 and a QHD screen (3800 x 1800) and scaled by WIn10, it is almost unusable. And not only the scrolling but general rendering performance. In comparison, Edge is 3 times faster with perfect scrolling. What is going on ??
Hi guys,

I was looking over this issue and tried to reproduce it on latest Nightly (47.0a1-20160201030241). Comparing the Firefox scrolling with the Edge scrolling I can say too that Edge has a smoother scroll, at least visual, but scrolls the lines slower than Firefox. 

On Nightly with APZ enabled + smooth scrolling checked the scrolling is almost as good as on Edge when slowly scrolling and deprecates a bit when scrolling faster the page content. 

Is this an improvement or it's the same as before ? Can you please retest this David on latest Nightly ( and report back ?

Flags: needinfo?(David-peters)
(In reply to Paul Oiegas [:pauloiegas] from comment #5)

> On Nightly with APZ enabled + smooth scrolling checked the scrolling is
> almost as good as on Edge when slowly scrolling and deprecates a bit when
> scrolling faster the page content. 
> Is this an improvement or it's the same as before ? Can you please retest
> this David on latest Nightly ( and report back ?

OK Paul, I tried Nightly 47 with APZ enabled and with and without smooth scrolling. Indeed, this is a major improvement, and actually quite usable.

However, it is still light-years from the MS Edge scrolling experience -- which feels as if there were a direct "metal" connection between the touchpad and the browser's viewport, with some "springiness" in that connection. Firefox with smooth scrolling otoh is not bad, but is still MUCH too soft, like stirring in honey as compared to the direct "metal" feeling of Edge. Without smooth scrolling FF is also very crisp, but still too "steppy".

Interestingly, the connection between the Synaptics touchpad and both FF and Edge obviously is not based on "mousewheel notches" anymore, but is more direct and with smaller (sub-line sized) increments. This again is still much better in Edge however, where it is both crisp (no trace of FF's stringy honey "smooth" scrolling) AND steps/scroll increments are not noticeable. 

Moreover, Edge obviously has some sort of exclusive scrolling connection to the touchpad. As soon as a page is scrolled in Edge, the cursor is fixed to its current position, instantly gets hidden and STAYS HIDDEN (potentially indefinitely) until pointing is resumed. In other words, as soon as you start scrolling (with a modern touchpad, that is), Edge enters an exclusive scrolling mode, locks itself in that mode and stays there forever -- or until you put exactly one finger down AND start moving that finger.

This is also INCREDIBLY useful because in contrast, with Firefox it happens all the time that the cursor -- while you actually were going to continue scrolling -- erroneously thinks you were already pointing again and jumps all over the place, while at the same time the page is not scrolled. Note that of course this is on the same hardware with both browsers side-by side.

Summarizing, Microsoft  Edge still beats everything, scrolling-wise, that ever has been seen on a computer to date, by a LARGE margin.
Flags: needinfo?(David-peters)
Thanks for the update. There's probably more we can do to improve this but it might have to wait a few releases while we get other high-priority items fixed up.
Summary: terrible FF scrolling performance as compared to Microsoft Edge Browser → FF scrolling performance still not as good as Microsoft Edge Browser
Depends on: 1199807
No longer depends on: apz-desktop
Depends on: 890878
No longer depends on: 1199807
THE benchmark to beat is probably a long e-mail full of images viewed and scrolled in Gmail. Such content does not scroll smoothly even with FF Nightly, apart from the problem that the cursor keeps forgetting that your are in scrolling mode and jumps around instead of scrolling -- a problem that is completely absent in Edge.

Interestingly, Edge also only scrolls the Gmail reading pane when the cursor is over the very pane, not when the cursor is over the scrollbar, while Nightly also scrolls when hovering the scrollbar.

Again, Edge for the first time brings IOS scrolling magic to Windows, while everything else on Windows including Firefox still scrolls the old Windows way: geeky, jerky and awkward :(
Keywords: perf
Whiteboard: gfx-noted
And why oh why is it that on a year 2016 monster PC with the fastest CPU available and with a gaming rated graphics card Firefox is not able, when loading a page in the background, to SLOW THAT BACKGROUND PROCESS down, instead of the foreground process, leading to choppy scrolling and bad responsiveness in the active tab until literally the last pixel has been placed in that background tab?!
Microsoft put a lot of thought into smooth scrolling. They don't even fire mouse wheel events to ensure javascript doesn't interfere with 60fps scrolling:

They use PTP pointer events instead.
Severity: normal → S3

Reporter, are you still experiencing this issue?

Flags: needinfo?(David-peters)

Redirect a needinfo that is pending on an inactive user to the triage owner.
:botond, since the bug has recent activity, could you have a look please?

For more information, please visit BugBot documentation.

Flags: needinfo?(David-peters) → needinfo?(botond)

We have made a lot of improvements to scrolling since the time this bug was filed, including using the Direct Manipulation API to get pixel scrolling for precision touchpads (bug 1630912 / bug 1671235) and bringing our scrolling animation physics more in line with platform conventions (bug 1418822).

I'm going to close this; if anyone is still experiencing a worse scrolling experience in Firefox than Edge, I encourage you to file a new bug with specifics.

Flags: needinfo?(botond)
Closed: 6 months ago
Duplicate of bug: 1671235
Resolution: --- → DUPLICATE
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