1225132 - Firefox interface is horribly laggy in a variety of situations, with delayed scrolling and typing

Status: RESOLVED WORKSFORME

(Firefox :: General, defect, P1)

Description

[Alberto Salvia Novella]

User Agent: Mozilla/5.0 (X11; Ubuntu; Linux x86_64; rv:42.0) Gecko/20100101 Firefox/42.0
Build ID: 20151030083518

Steps to reproduce:

As soon as a Firefox operation is somehow intensive, it makes the interface performance to be affected.

It can be certain addon or engine, like loading a page with plenty of graphics. No matter what processor or graphic card you have. Even when it would perform better with more modern hardware, performance will suffer equally under certain situations.


Actual results:

The interface lags, with choppy scrolling and typing. This single problem is making many Firefox users to quit, and go with Chrome instead:

https://www.google.com/trends/explore#q=firefox%2C%20chrome&cmpt=q&tz=Etc%2FGMT-1


Expected results:

The Firefox interface should be separated from its engine, and have a higher execution priority that it. It should also take advantage of multi-threading.

Comment 1

[frederik]

I definitely experience this problem as well. I'm not sure if it's the amount of Javascript on certain web pages, or the amount of stuff that they're trying to load in the background (my ISP connection is "slow"), but scrolling and interacting with the browser becomes very painful until the pages are fully loaded. Chrome is much better but also has some issues. Popular, image-heavy websites like Amazon.com and Facebook.com are the worst offenders.

For what it's worth, I believe that laggy interfaces are harmful to the nervous system - for example I notice my right index finger, which I use to operate the mouse scroll wheel, starts to hurt when I use Amazon in Firefox for too long. I do not experience the problem when using websites where Firefox can scroll without significant latency.

Many websites, like Facebook and Amazon, now load content in the background while the user is scrolling. This means that waiting for the page to "fully load" before trying to interact with it is not really an option. From a software engineering perspective, I could be missing something, but it seems that it should be possible to have a cheap internet connection without sacrificing UI responsiveness in the browser.

Comment 2

[Frederick Eaton]

Update: I bought a new computer, but still have the same internet connection. With 16GB RAM and a 3.5GHz processor, there is no lagginess on most websites. With 1GB RAM and a 1.6GHz processor, there was a lot of lag.

'top' on the faster computer:

  PID USER      PR  NI    VIRT    RES  %CPU %MEM     TIME+ S COMMAND                                                             
 2307 frederik  25   5  805.1m 280.3m   0.0  1.8   0:38.66 S firefox                                                             

'top' on the slower computer:

  PID USER      PR  NI    VIRT    RES  %CPU %MEM     TIME+ S COMMAND                                                             
 7783 frederik  25   5 1247.0m 387.1m   2.6 38.9  49:44.03 S firefox

Comment 3

[Panos Astithas (he/him) [:past] (please ni?)]

With e10s shipped this should be now fixed.