GTK2 and sluggishness on old machines [SOLVED]

Gullible Jones · 2011-09-13 21:59:43

I recently installed Debian on a 450 MHz Macintosh with 500 MB of RAM.

The command line is quite fast. Heck, Xorg is quite fast - Xpdf renders everything very quickly thank you. And this is with the notoriously slow fbdev driver too. (fbdev is the only one that works.)

Unfortunately, most of the desktop is GTK2 applications. And these are all excruciatingly slow. Firefox especially, but even Thunar renders its widgets slowly, and jerks and wiggles about when I move the window.

Is there any way to remedy this? Other toolkits don't display the same sluggishness. Furthermore, GTK2 is quite fast on other platforms, e.g. on Windows it renders stuff as fast as any other toolkit. Why should it be so slow on Linux?

Edit: err, some clarification in case anyone wonders why I'm posting in OT. I tried asking about this on the Debian forums, but nobody seemed to know the answer.

Last edited by Gullible Jones (2011-09-14 00:47:57)

karabaja4 · 2011-09-13 22:14:40

GTK2 rendering just sucks, I'm guessing the code isn't pretty. It's not something that can be helped, workaround is to use different toolkits.

GTK3 and QT render alot faster. Luckily there are number of QT/GTK3 applications available to replace ones written in GTK2. Except browsers I guess, Chromium is pretty fast though, even though it is GTK2 - its code is pretty deep. Epiphany looks promising as a GTK3 browser.

Last edited by karabaja4 (2011-09-13 22:18:08)

pogeymanz · 2011-09-13 22:20:01

Are you using the default GTK2 theme?

That's basically as fast as GTK2 can get. It is unfortunately slow. I don't know if GTK3 or Qt will be better on such old hardware. Look for things built with the fox toolkit or TK.

A good file browser is xfe.

Gullible Jones · 2011-09-13 23:13:38

Gah.

The major hurdle in this case is Firefox. Firefox doesn't have a fast GUI to start with, and with the GTK2 sluggishness it's just unusable. I've tried several things...

- Exporting MOZ_DISABLE_PANGO=1: no visible improvement. I'm not sure this variable is even valid with Debian's build.
- Using a Firefox theme instead of the desktop theme: I figured that letting XUL do its own thing might help, but it doesn't.
- Using the autohinter: Makes fonts look a bit nicer, but doens't improve performance.
- Using the XFS and XFSTT font servers: does nothing at all, as far as I can tell. I'm not sure XOrg even acknowledges these servers any more.
- Disabling antialiasing: No performance improvement, and makes all the fonts unreadable. Yay.

Firefox works perfectly on similarly low-end x86 machines running Windows 2000. IMHO there is no freaking reason anyone should need a gigahertz-plus CPU to run a modern browser just because they're using Linux.

(I'll also note that Abiword, another GTK2 program, is fast on Windows and slow on Linux. Seems ridiculous, no? Doesn't GTK2 use the same backends on both platforms?)

Gullible Jones · 2011-09-14 00:27:34

pogeymanz wrote:

Are you using the default GTK2 theme?

Ah, missed that! No, I was letting Xfce use its default theme - Clearlooks I think. Duh.

I just switched to the Raleigh theme on my G4, and the difference is huge; Thunar refreshes instantly, and Firefox, while still sluggish, is much faster. I had no idea that GTK themes were that slow. I'll have to try this on the G3 if I get the chance.

(And I think this explains the performance on Windows. GTK2 widgets on Windows use Raleigh by default, and just inherit the colors of the current Windows widget theme.)

karabaja4 · 2011-09-14 00:51:44

Another theme that is pretty fast is "Mist", it's a good balance between performance and looks.

Gullible Jones · 2011-09-14 02:10:01

Thanks, but for now I think I'll stick with my fast unthemed desktop and gradient wallpaper

On another note, I wonder if there's something broken in the way GTK theme engines are implemented..

pogeymanz · 2011-09-14 13:31:58

Gullible Jones wrote:

Thanks, but for now I think I'll stick with my fast unthemed desktop and gradient wallpaper
On another note, I wonder if there's something broken in the way GTK theme engines are implemented..

It's just the way some engines draw their stuff. The Pixmap engine is particularly slow because, of course, it uses pixmaps for images which are big and bulky.

The xfce engine is actually pretty fast. If you use the default xfce gtk theme (not clearlooks), it should be pretty responsive. Same for Mist theme, Raleigh, etc. The Murrine engine is slower than those, but much faster than most of the "pretty" theme engines.

You can google for benchmarks or do your own with gtkperf.

Gullible Jones · 2011-09-14 14:01:03

Say, just a thought: GTK2 apparently double buffers almost everything on the widget level. Is there a way to disable that? Because that would probably slow certain operations on low-end machines.

(Disabling the X Double Buffer Extension wouldn't work for this purpose unfortunately, GTK2 does its own buffering.)

Last edited by Gullible Jones (2011-09-14 14:01:30)

Arch Linux

#1 2011-09-13 21:59:43

GTK2 and sluggishness on old machines [SOLVED]

#2 2011-09-13 22:14:40

Re: GTK2 and sluggishness on old machines [SOLVED]

#3 2011-09-13 22:20:01

Re: GTK2 and sluggishness on old machines [SOLVED]

#4 2011-09-13 23:13:38

Re: GTK2 and sluggishness on old machines [SOLVED]

#5 2011-09-14 00:27:34

Re: GTK2 and sluggishness on old machines [SOLVED]

#6 2011-09-14 00:51:44

Re: GTK2 and sluggishness on old machines [SOLVED]

#7 2011-09-14 02:10:01

Re: GTK2 and sluggishness on old machines [SOLVED]

#8 2011-09-14 13:31:58

Re: GTK2 and sluggishness on old machines [SOLVED]

#9 2011-09-14 14:01:03

Re: GTK2 and sluggishness on old machines [SOLVED]

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