[mactropolis]

Hi All,
I am a longtime Firefox on PC user and recently got a new Mac with a pretty spiffy Core 2 Duo processor. I am totally impressed with the speed of the machine, except Firefox scrolling performance when Smooth Scrolling feature is activated. (Preferences > Advanced > "Use smooth scrolling")

Firefox (w/ option enabled) and IE7 both have visually appealing smooth scrolling on even very basic XP PC's with almost no CPU spike. Safari on Tiger comes along with a reasonable 10-20% CPU reported by 'top' utility and minimal Activity Monitor.app CPU Usage palette animation (Both cores level out at about quarter).

Firefox on OS X? When I enable the option in Firefox 2.X I notice it pulls sustained 50-60+% CPU easily simply by scrolling with mouse scroll wheel actively on a long page. Activity Monitor CPU Usage palette easily shows both CPU cores easily reaching 50%+ sustained for the duration of the smooth scrolling action. I've also noticed about 25-30% CPU by scrolling using scroll bar (apparently mouse wheel vs. scroll bar makes a difference). Both cases seem excessive.

I know Firefox isn't exactly a 'lite' its toes (Carbon vs Cocoa, XUL, etc), but assumed it shouldn't be taxing a Core 2 Duo CPU in the 55%+ CPU range just for something as basic as smooth scrolling. I love Mac, yet prefer Firefox (compatibility & extensions), and my eyes have just grown very accustom to smooth scrolling all the years from PC Firefox & IE.

1) Is this the standard behavior for Firefox with smooth scrolling activated on a Mac ??
2) Any solution (short of disabling smooth scrolling/ditching Firefox) ??


PS. Same results on several pages tested. No plugins active on page (Quicktime, Flip4Mac, etc). Flash blocked using Flashblock. Advert images blocked (No animated GIFS). Stock Firefox profile. Javascript enabled. Fresh launch.



Thanks!

[Cadaver]

Firefox doesn't really use any Mac-native routine for much of what it does. While I'm no programmer, I would imagine that Firefox basically has to rerender the whole page, including text/menu widgets, every time you move the scroll bar. On the other hand, Firefox on Windows uses fully OS-native buttons, widgets, etc., making scolling essentially an OS job, not a job of the application. I'm a bi-platform person (sounds weird, doesn't it), so I'm very familiar with how Firefox works on Windows.

Just my theory...

[gro]

Maybe you could try to install the SmoothWheel extension: mozdev.org - smoothwheel: index
YMMV, but in my case after changing some of the settings (fps limit = 50fps for example) the cpu usage while scrolling was a lot less.

[mactropolis]

Thanks!
Will investigate the Smoothwheel extension when I return home. But does it make the smooth scrolling less visually appealing (ie. less FPS == more jerky, etc) ?

[mactropolis]

Hey all!
Finally got a chance to try that Smoothwheel extension and am thrilled to say it did the job! I have smooth scrolling in Firefox with a reasonable 15-20% CPU, half of before. Amazingly, the scrolling looks even better than Gecko's default algorithms anyway, so Win-Win.

Thanks gro!

[Sethro]

Agreed the Firefox development team needs some tight Mac OSX integration they have promised some features like Keychain integration and an improved user interface for Mac users. But really the only thing thats holding me back from using Safari only are some of FIrefox's extensions, in many cases they are life savers.