Why is scrolling on Linux so much slower than on Windows?

Bazon · Post by **Bazon** » March 22nd, 2008, 4:10 am

Hello!

I made a Greasemonkey Script which includes a kind of automatic scroll function, and I noticed that Scrolling is significant slower on Linux than on Windows.
(That's also an impression I had about manual scrolling....)

Here's a quick and dirty webpage to demonstrate this phenomena:
http://home.arcor.de/bazonbloch/scrollt ... indows.htm
(Including information about my System and measured scrolling times...
....hit the arrows to trigger auto-sroll!)

So my question is:
Is this a known Bug?
Should it be filed?
Or can I do something to avoid this behaviour?

I searched in bugzilla but I haven't found something clearly matching this.

Post by **steviex** » March 22nd, 2008, 4:25 am

Which Distribution are you using ? Which Window Manager ? Are you using Compiz/Beryl to create whizzy effects ?
Do you have any display related extensions installed ? What Theme are you using ?

I'm using Ubuntu 7.10 (Gutsy Gibbon) using GNOME with Compiz enabled
Mozilla/5.0 (X11; U; Linux i686; en-GB; rv:1.8.1.12) Gecko/20080207 Ubuntu/7.10 (gutsy) Firefox/2.0.0.12

I get these scores.... Scrolling up has taken 1363 ms. Scrolling down has taken 1429 ms.

Have you tried any other Linux distributions or KDE if you were using GNOME ??
Also have you tried in Safe Mode... http://kb.mozillazine.org/Safe_Mode
It could be an extension or Theme that is causing the slow scrolling.

Bazon · Post by **Bazon** » March 22nd, 2008, 4:49 am

steviex wrote:Which Distribution are you using ?

Ubuntu 7.10 (Gutsy Gibbon)

steviex wrote:Which Window Manager ?

XFCE or Compiz on XFCE (triggered by compiz-switch)

steviex wrote:Are you using Compiz/Beryl to create whizzy effects ?

Yes, but turning Compiz of (by compiz-switch) doesn't make such a big difference:
with Compiz on: about 3500ms
with Compiz off: about 3000ms
(which is both significant slower than on windows where it takes about 1220ms)

steviex wrote:Do you have any display related extensions installed ? What Theme are you using ?

I'm using the same profile on windows and Linux (I copied the profile folder), so that shouldn't make a difference.
I use the default theme and this extensions.
But the extensions seem to have no effect on the scrolling behavour:
I also tried it in safe-mode (yes, the promt window told me I was really in safe-mode...) and got exactly the same time-scores.....

steviex wrote:I'm using Ubuntu 7.10 (Gutsy Gibbon) using GNOME with Compiz enabled
Mozilla/5.0 (X11; U; Linux i686; en-GB; rv:1.8.1.12) Gecko/20080207 Ubuntu/7.10 (gutsy) Firefox/2.0.0.12

So do I, exept XFCE instead of Gnome an official Firefox instead of Ubuntu-Firefox:
Mozilla/5.0 (X11; U; Linux i686; de; rv:1.8.1.12) Gecko/20080201 Firefox/2.0.0.12

steviex wrote:I get these scores.... Scrolling up has taken 1363 ms. Scrolling down has taken 1429 ms.

Interesting, but IMHO it's no use comparing your system to mine, but comparing Windows and Linux on the same hardware.
As I wrote on the testpage, my system is quite slow:
My System: AMD Geode 1750 Nx, 1,4GHz, 1024MB RAM, Nvidia GeForce FX 5200LE
I suppose you have a faster one (like most most users will have...)
(and if you have a faste one: on my system it scrolls still faster on Windows: about 1220ms)

steviex wrote:Have you tried any other Linux distributions or KDE if you were using GNOME ??

No, I haven't tried other distributions yet, but I will make a test on Knoppix soon....
But in fact I tried using Gnome instead of XFCE, that made absolutly no difference.

steviex wrote:Also have you tried in Safe Mode... http://kb.mozillazine.org/Safe_Mode
It could be an extension or Theme that is causing the slow scrolling.

Yes, I did. (See above...)
No difference.

Post by **BenBasson** » March 22nd, 2008, 4:59 am

Probably something to do with the fact that your background image is 1600x1200 pixels.

Bazon · Post by **Bazon** » March 22nd, 2008, 5:00 am

OK, here I am again on

knoppix@0[knoppix]$ uname -a
Linux Knoppix 2.6.12 #2 SMP Tue Aug 9 23:20:52 CEST 2005 i686 GNU/Linux
with default Firefox:
Mozilla/5.0 (X11; U; Linux i686; de-DE; rv:1.7.10) Gecko/20050911 Firefox/1.0.6 (Debian package 1.0.6-5)

and here is a suprise:

On Knoppix (with KDE), scrolling ist clearly faster than on Ubuntu, but still slower as on windos:
It takes about 1900ms.
(Ubuntu, Compiz: 3500ms,
Ubuntu, Compiz-off: 3000ms,
Windows XP: 1220ms)

But OK, you see, this is a very old version of firefox.

I try to get the momentary Version of Firefox running on this Live-System and will report again.....

Bazon · Post by **Bazon** » March 22nd, 2008, 5:03 am

@Cusser:
But the background image has the same size on all Operating Systems!
Does that explain the difference?
(And in my Greasemonkey script, I use a background image which is only 1280 x 1024 px² big, it's still the same effect....)

Post by **BenBasson** » March 22nd, 2008, 5:06 am

It's slow and jerky for me on Windows with a PC much more powerful (see my forum signature) using Firefox 3.0b5pre nightly builds. Trimming the image to just the Firefox logo immediately solved the problem.

Bazon · Post by **Bazon** » March 22nd, 2008, 5:09 am

Oops!

I suppose you won't be happy to read that:

I'm still on Knoppix
knoppix@0[knoppix]$ uname -a
Linux Knoppix 2.6.12 #2 SMP Tue Aug 9 23:20:52 CEST 2005 i686 GNU/Linux

but this time with the official momentary firefox-version:
Mozilla/5.0 (X11; U; Linux i686; de-DE; rv:1.8.1.12) Gecko/20080201 Firefox/2.0.0.12

and it is slow as on Ubuntu (without Compiz) again!!!
about 3000ms.

So unfortunatly, Firefox Mozilla/5.0 (X11; U; Linux i686; de-DE; rv:1.8.1.12) Gecko/20080201 Firefox/2.0.0.12 is slower than Mozilla/5.0 (X11; U; Linux i686; de-DE; rv:1.7.10) Gecko/20050911 Firefox/1.0.6 (Debian package 1.0.6-5) !!!!

-hm....

Post by **BenBasson** » March 22nd, 2008, 5:11 am

Looks like you might have found a performance regression there. I get faster scrolling on Windows with 2.0.0.12 than with 3.0b5pre.

Bazon · Post by **Bazon** » March 22nd, 2008, 5:18 am

....and it seemed to be even faster on Firefox 1.06! (See my frst Knoppix test...)

I mean:
Such different performances on the same page with different versions of Firefox, that shouldn't be! Should it?

Post by **BenBasson** » March 22nd, 2008, 5:29 am

Firefox 3 is very different to Firefox 2, which is very different to Firefox 1, especially if you start looking at versions running on different operating systems, so I can't say I'm surprised.

Older versions are a lost cause, but you could probably file a bug on the basis that this used to be faster and give your findings. What I'm seeing on Windows XP is:
2.0.0.12: 1200-1300ms
3.0b5pre: 2300-2400ms and is noticeably jerky.

If you do file a bug, please post back with the number and I'll confirm it.

Post by **steviex** » March 22nd, 2008, 5:29 am

Just to add my stats in Windows
Mozilla/5.0 (Windows; U; Windows NT 5.1; en-GB; rv:1.8.1.12) Gecko/20080201 Firefox/2.0.0.12

Down 1234 Up 1312

You may be on to something there....

By the way SeaMonkey 1.1.8 in Windows got 1297 down and 1140 Up....

Bazon · Post by **Bazon** » March 22nd, 2008, 5:33 am

So what do you think:

Should this be filed as a bug?

On what component?
On what OS?

I really got no idea....

Post by **BenBasson** » March 22nd, 2008, 5:36 am

Yes, definitely. My best guess would be Core/GFX, all operating systems. Summarise your data so it's as easy to read as possible (small list of version, OS, scroll times or something). Definitely mention that on older builds you're only seeing this on Linux if that's the case.

Post by **BenBasson** » March 22nd, 2008, 5:50 am

Scrolling is faster when less of the image is visible. If I make my browser window only an inch or two tall, I get close to 1200ms. This seems to drop in a linear way as I increase window size.