Fast scrolling via the scroll box is more laggy than in NS4.7 on old Macs




17 years ago
16 years ago


(Reporter: benjamin, Assigned: kmcclusk)



Mac System 8.6

Firefox Tracking Flags

(Not tracked)





17 years ago
This is a very general observation but on old Macs: Mozilla lags/"skip" on fast
scrolling. More fluide behavior could be appreciated at lease as it,s was in NS4.7.

Comment 1

17 years ago
Reporter, how old is old?

Comment 2

17 years ago
Sorry ;-)

PowerMac 7600/8500/8600 with G3/400Mhz card
Some with ATI Orion Cards

Comment 3

17 years ago
Assignee: asa → karnaze
Component: Browser-General → Layout
QA Contact: doronr → petersen

Comment 4

17 years ago
Reporter, can you provide some concrete details on the differences between scrolling in 
Nav 4.x and Mozilla on the machine in question? For example, load on both and 
measure how long it takes them both to scroll to the bottom of the page by clicking and 
holding the scroll down arrow.

Comment 5

17 years ago
It's not laggy when I use arrows (It's perfect) but when I drag quickly the 
scroll box...It's like if Moz skips "frames", it's not fluide... For exemple the 
scroll box/window content "freeze" and jumps one inch between redraw... That 
isn't not critical but the behavior of other browsers (on same Macs) is more 
fluide and it's btw more simple to find contents on a (long) web pages.

Comment 6

17 years ago
Okay, but again, some quantitative data would really help the engineers address this 
problem. They're just going to have to do it themselves once they get to this, and it'll get 
fixed (if possible) faster if they don't have to.

It could be that the best, easiest fix is to disable live scrolling on those older machines.

Comment 7

17 years ago
Really don't know how I can quatify this. To do this I need some thing to 
benchmark like frames by sec or whatever...

Good page to test this behavior is:

BTW I made some tests:

NS4.78 is the more fluide in live scrolling
IE and Opera second
Moz the last

I think if NS is able to be the best Moz can beat it.

> It could be that the best, easiest fix is to disable live scrolling...

The laggy behavior is better than nothing. 

HW ref:
ATI ORION 16MB / 1280*1024 / Millions of colors

-> Change summary
Summary: Fast scrolling is more laggy than in NS4.7 on old Macs → Fast scrolling via the scroll box is more laggy than in NS4.7 on old Macs

Comment 8

17 years ago
After loading that URL in both Mac IE 5 and Mac Mozilla 0.9.3, scrolling performance is 
approximately identical, with Mozilla having perhaps a very slight edge.

I, however, have a 466 MHz G4 with an ATI Rage 128 Pro, so my video performance is 
going to be better than yours, in general.

This seems like one of those issues with Mozilla performance on Macs near the bottom of 
its' system recommendations.

Comment 9

17 years ago
To Mac Mozilla's credit, it should be pointed out that the URL in question took 40 
seconds to load in Mac IE 5, and 8 seconds just to close the window. Mozilla loaded the 
page in 20 seconds and the window closed in 2 seconds.

Comment 10

17 years ago
Reporter, try scrolling at different color depths; let us know if there's any appreciable 
difference in scrolling speed.

Comment 11

17 years ago
No "appreciable difference" in scrolling speed with different color depths

At a same dragging speed of the scroll box NS give me around 20 "scroll box/
content redraw" vs around 5 in mozilla. If I compare the behavior to a QT Movie 
it's like if in NS the frame rate was about 24fps and in Moz around 5-7fps while 
I scroll by dragging the scroll box ... If I scroll "slowly" or use arrows Moz is 
perfect as I said before...

Comment 12

17 years ago
Karnaze, is this the right component? Should it perhaps go to XP Apps: GUI Features? 
What controls scrolling?

Comment 13

17 years ago
It could be scrolling or painting performance. Let's start with scrolling. 
Reassigning to evaughan.
Assignee: karnaze → evaughan

Comment 14

17 years ago
setting bug status to New
Ever confirmed: true

Comment 15

17 years ago
btw it's also true in the Mail & Newsgroups window when lot of messages are
listed in the same folder or on very long email... Quite annoying on *fast
search* by scrolling.

Comment 16

17 years ago
Taking this bug
Assignee: eric → kmcclusk
Target Milestone: --- → mozilla1.0.1

Comment 17

17 years ago
Bulk moving Mozilla1.01 bugs to future-P1. I will pull from the future-P1 list
to schedule bugs for post Mozilla1.0 milestones
Priority: -- → P1
Target Milestone: mozilla1.0.1 → Future


16 years ago
Priority: P1 → P3

Comment 18

16 years ago
Mach-O is fast enough, and of course
Mozilla CFM build is dead.
Last Resolved: 16 years ago
Resolution: --- → WONTFIX
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