1635633 - Webrender enabled in 76.0 on Intel 8145U, degraded performance greatfully

Status: RESOLVED INCOMPLETE

(Core :: Graphics: WebRender, defect, P3)

Description

[nidza.bg]

User Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:76.0) Gecko/20100101 Firefox/76.0

Steps to reproduce:

Hello,

I've a HP Laptop with an i3 8145U CPU (it's 8th gen refresh). As soon as it updated to firefox 76, I opened up a simple forum, and the scrolling was completely stuttering. Then I opened up google to search for what's going on and I found out that webrender got enabled for my CPU. I went to about:support and yes indeed it was enabled, but the performance was AWFUL.

Actual results:

Performance degradation. I'm currently on battery power. The only way to disable it was not to edit the default boolean setting, but it had to be forced turn off. It might work differently on battery power or desktop CPUs but on laptops it's really working awful.

Expected results:

I guess I just wanted performance to be as it used to be. I've a NVMe drive, UHD620 graphics, 8145U CPU and 8 gigs of single-channel RAM. The laptop works flawlessly and was working excellent till the update came. It just can't handle the webrender. I've switched back to DirectX and it's working fine again.

Comment 1

[nidza.bg]

Additional testing proved that simple web pages also do stutter, even simple HTML CSS-less and JS-less. Also the UI of the Firefox is not working well, it stutters while opening the bookmarks quick link. So, the lag as I may call it seems present everywhere.

Comment 2

[BugBot [:suhaib / :marco/ :calixte]]

Bugbug thinks this bug should belong to this component, but please revert this change in case of error.

Comment 3

[GMA]

https://downloadcenter.intel.com/download/29554/Intel-Graphics-Windows-10-DCH-Drivers

Can you test on the latest Intel 27.20.100.8187 driver and see if this still happens?

Comment 4

[Jeff Muizelaar [:jrmuizel]]

Can you post the graphics section of about:support as well as some of the urls that you see the performance problems?

Comment 5

[Tim Spurway [:tspurway]]

Jessie, could you review the severity (s2) and set priority on this one?

Comment 6

[Darkspirit]

0x3ea0 was added by bug 1547702. Intel small screen without battery shipped with Firefox 70.

(Jeff Muizelaar [:jrmuizel] from comment #4)

Can you post the graphics section of about:support as well as some of the urls that you see the performance problems?

Nidza.bg, please type about:support into your adress bar, press enter, click on the "copy text to clipboard" button and paste it here. Thanks!

Comment 7

[Jessie [:jbonisteel] pls NI]

Without getting more information from the reporter, it is hard to know the true severity. I have also emailed this reporter directly to try and get their about:support info.

Comment 8

[nidza.bg]

Attachment: about:performance for the WebRender bug

Comment 9

[nidza.bg]

Hello people,

I'm sorry, been AFK for some personal issues for the last couple of days. I'm back now and really sorry that you spent this much time with the issue without me. Anyways, I'm back now. Jessie, I've recieved your e-mail, thanks for contacting me directly. We can continue here or via e-mail, whichever you prefer.

I've re-enabled the WebRender instead of DX to test it again. DX works flawlessly, but just opened up about:support, and just scrolling it with my 2 fingers on the touchpad it chops and stutters at one point. I'm not sure if recording a video with 60FPS via my phone or something would help.

Is webrender more GPU intensive, is it more CPU intensive? That might help to track down the issue, since 8145U CPU is made to be super efficient. I get around 4.5W to 5.5W total power usage on this laptop doing regular tasks - programming, compiling, browsing, background music, watching videos/netflix/yt, etc. Could it be win10 power options that throttle the CPU and therefore make it choppy? On my desktop with a overclocked FX8370E 8-core @ 4.7GHz with an Nvidia GTX970, I'm using WebRender and got no issues at all. I'll try playing with power profiles (win10 has 4 of them while on battery) and see if there's any difference, but so far, scrolling is most affected.

I've attached my about:support to the link you specified, and would be glad to run any more tests to track down the issue. If it is Win10 CPU throttling, it will affect many probooks or lightweight laptops with this config.

Also, in about:performance, when I open a single Facebook tab, the energy impact is really, really high. Just keeping it open I get around 15-25 (sometimes peaking at 65+) units (not sure what the numbers represent) and later it settles down to lower than 5 and jumps again. On DX rendering it doesn't ever come close to that.

Comment 10

[Jeff Muizelaar [:jrmuizel]]

The about:support page has some particular issues can make it work poorly in WebRender. Can you make a list of other urls where you see worse behaviour with WebRender on?

Comment 11

[Rachel Tublitz [:rachel]]

S1 or S2 bugs need an assignee - could you find someone for this bug?

Comment 12

[Jessie [:jbonisteel] pls NI]

We need more information from the reporter to take action or know more about the genuine severity of this bug.

Comment 13

[Jessie [:jbonisteel] pls NI]

The about:support page has some particular issues can make it work poorly in WebRender.

Jeff, can you elaborate on this?

Comment 14

[Jeff Muizelaar [:jrmuizel]]

about:support runs in the parent process (which maybe means it doesn't have apz) and suffers from long display list build times because it has large blocks of text. It also seems to have a blob image issue (perhaps because of borders)