Firefox Developer Edition: Extreme UI lag

Batou · 2020-02-01 00:41:50

Hi all,

I'm trying to switch to Firefox for all my daily use and have picked the Developer Edition because of a few niceties that it offers (plus I'm a webdev).
One thing that's bothering me immensely is the UI lag. When I select the menu button or right click anywhere, the UI highlighting does not follow the cursor. It always lags and often it doesn't even show up as highlighted. I can still click on everything and everything works but the perceived UI lag is extremely annoying.

Here's a short video: https://gfycat.com/singledifficultbooby

I can click on anything and it's fast but the UI just doesn't follow the mouse cursor.

I've tried it with Xfce and Cinnamon and the results are identical. It just lags. I have no extensions installed and have tried it in Private mode. The results are identical... it lags.
This is also not a new issue... many months ago I installed Firefox Dev and have noticed the same issue but didn't bother trying to find the root cause.

Does this happen to anyone else? Does this happen to other editions of Firefox? Anyone have any recommendations as to how I can get this fixed?

Thanks for any insight!

Edit: Oh, and this does not happen to any other application I'm using (don't think I've ever encountered this issue with any other program I've used so far).

Last edited by Batou (2020-02-01 01:11:06)

V1del · 2020-02-01 12:52:51

Doesn't happen on normal firefox here. What's your graphics card and DDX driver ? Also check some of the settings you can set here like: https://wiki.archlinux.org/index.php/Fi … ing_(OMTC)

Batou · 2020-02-01 22:34:55

V1del wrote:

Doesn't happen on normal firefox here. What's your graphics card and DDX driver ? Also check some of the settings you can set here like: https://wiki.archlinux.org/index.php/Fi … ing_(OMTC)

Thanks for a reply V1del!

I have an Nvidia card and use Nvidia's binary driver.

OK, so in my case Firefox Developer reported Compositing as WebRender. https://i.imgur.com/o5lS7OQ.jpg

Main trunk Firefox reports Compositing as Basic after the install and looks like this: https://gfycat.com/digitalgenuineagouti Zero issues. Even after I enabled OpenGL on regular Firefox, it still rendered everything without a lag. https://i.imgur.com/mAwOfcp.jpg

So is the issue this WebRender technology? I had no idea what that was so I looked it up:

Enables WebRender compositor in Servo, instead of Gecko. It improves performance on supported hardware, fixes some black visual glitches when "OpenGL Off-Main-Thread" is enabled. Currently it has some known bugs. You can read more in MozillaWiki:Platform/GFX/Quantum Render.

I never enabled this by default so I presume Mozilla enabled this in Developer branch?

Anyway, after disabling WebRender so the compositing is set to OpenGL, lag still remains: https://gfycat.com/ablehatefulindianpalmsquirrel

I've been looking at various settings and looking at the differences between regular and Dev and they all look the same to me.

I don't know... I'm out of ideas. I could rm whole firefox-developer config folder and remove all settings, tabs, extensions and start from scratch. Or just use the regular Firefox.

Last edited by Batou (2020-02-01 22:38:38)

seth · 2020-02-01 22:46:05

> I've tried it with Xfce and Cinnamon and the results are identical.

Try w/o any compositor (openbox or. iirc you can deactivate the one in xfwm4) in case FF generates insufficient or no damage events.
It also might be a vsync issue (if FF does and stumbles over the refresh rate detection) - maybe there's a config key to deactivate vsync or enforce a RR?

Batou · 2020-02-01 23:03:08

seth wrote:

> I've tried it with Xfce and Cinnamon and the results are identical.
Try w/o any compositor (openbox or. iirc you can deactivate the one in xfwm4) in case FF generates insufficient or no damage events.
It also might be a vsync issue (if FF does and stumbles over the refresh rate detection) - maybe there's a config key to deactivate vsync or enforce a RR?

Hi seth!

Just tried it with Openbox... same issue. Your comment also reminded me that I have enabled 'Force Composition Pipeline' in Nvidia settings so I tried disabling it. Same issue persists. I've also tried disabling "Use Smooth Scrolling" in Firefox Dev's main Preferences but that didn't change anything either.

It's really weird.

seth · 2020-02-02 09:09:04

Forcing the composition pipeline will make nvidia treat the display as if it was eg. scaled, ie. makes the global rendering more expensive and keeps the GPU in performance mode. I don't think it's impact can break partial content rendering.

Did you check about:config for vsync related settings?

Batou · 2020-02-02 23:39:01

seth wrote:

Forcing the composition pipeline will make nvidia treat the display as if it was eg. scaled, ie. makes the global rendering more expensive and keeps the GPU in performance mode. I don't think it's impact can break partial content rendering.
Did you check about:config for vsync related settings?

They seem to be identical:
Dev - https://i.imgur.com/cVu1HVU.png
Regular - https://i.imgur.com/iqFZrKi.png

Arch Linux

#1 2020-02-01 00:41:50

Firefox Developer Edition: Extreme UI lag

#2 2020-02-01 12:52:51

Re: Firefox Developer Edition: Extreme UI lag

#3 2020-02-01 22:34:55

Re: Firefox Developer Edition: Extreme UI lag

#4 2020-02-01 22:46:05

Re: Firefox Developer Edition: Extreme UI lag

#5 2020-02-01 23:03:08

Re: Firefox Developer Edition: Extreme UI lag

#6 2020-02-02 09:09:04

Re: Firefox Developer Edition: Extreme UI lag

#7 2020-02-02 23:39:01

Re: Firefox Developer Edition: Extreme UI lag

Board footer