Re: Is GTK+ 3.x 2x slower than GTK+ 2.x?

[Sergei Steshenko <sergstesh yahoo com>]

--- On Sat, 7/23/11, Jakub Misak <jmisak centrum cz> wrote:

> From: Jakub Misak <jmisak centrum cz>
> Subject: Is GTK+ 3.x 2x slower than GTK+ 2.x?
> To: gtk-list gnome org
> Date: Saturday, July 23, 2011, 12:30 PM
> 
> Is GTK+ 3.x 2x slower than GTK+ 2.x?
> 
> Hello,
> 
> When I upgraded to GTK+ 3.0, the first thing that struck me
> was how 
> sluggish it was compared to 2.24. The same dialogs in the
> same 
> application appear immediately on the screen in the 2x
> version, while 
> it takes time to paint them on the screen with the 3.x
> version. 
> Browsing through menus or switching between tabs consumed
> 2x or 3x more 
> CPU cycles in the 3.x version. The file open/save dialog is
> much slower 
> (slower to show up, slower to change directories). Or
> hovering over the 
> toolbuttons in 3.x-based Glade consumed 80% CPU cycles and
> the 
> highlighting could barely keep up with the mouse cursor.
> Application 
> startup is a bit slower with 3.x, too.
> 
> So I made a (very) simple and stupid benchmark that tests a
> couple of 
> basic things in a loop, to see how the two GTK+ versions
> compare. 
> If you're interested, you can download it here:
> 
> http://www.fileupyours.com/files/310686/perftest.tar.gz
> 
> (A simple "make" command should build both versions.)
> 
> I am testing it in xfwm4 with compositor turned off. If you
> test it in 
> a compositing WM with window effects (open/close),
> especially with 
> test #3 which opens/closes a dialog 50 times, it may
> measure something 
> else than GTK+ speed...
> 
> The default GTK+ theme (Raleigh) was used for both 2.24 and
> 3.0.11. 
> Both GTK+ 2.x and 3.x software was already running, so both
> library 
> versions were loaded in memory (so it was probably not an
> issue for the 
> startup speed).
> 
> The results from my 3GHz dual CPU desktop machine with the
> open-source 
> radeon driver (I ran each test 7 times and took the best
> result for each 
> test):
> 
> Startup, GTK+ 2: 0.11081 s, GTK+ 3: 0.14468 s
> Test 1, GTK+ 2:  4.34362 s, GTK+ 3: 8.83771 s
> Test 2, GTK+ 2:  1.72010 s, GTK+ 3: 2.33266 s
> Test 3, GTK+ 2:  2.27047 s, GTK+ 3: 4.79270 s
> 
> It's not just my computer, as I tried it on an HP 625
> laptop, again 
> using the radeon driver:
> 
> Startup, GTK+ 2: 0.09357 s, GTK+ 3: 0.13600 s
> Test 1, GTK+ 2:  3.27795 s, GTK+ 3: 5.20183 s
> Test 2, GTK+ 2:  1.47700 s, GTK+ 3: 1.46733 s
> Test 3, GTK+ 2:  1.35302 s, GTK+ 3: 5.14810 s
> 
> It's not the radeon driver either, as I tried it with the
> proprietary 
> fglrx driver, too:
> 
> Startup, GTK+ 2: 0.09058 s, GTK+ 3: 0.13770 s
> Test 1, GTK+ 2:  2.42151 s, GTK+ 3: 6.67091 s
> Test 2, GTK+ 2:  1.15294 s, GTK+ 3: 1.44557 s
> Test 3, GTK+ 2:  1.31779 s, GTK+ 3: 4.64865 s
> 
> It's probably not the default theme either. First, the
> default themes 
> look very similar in both versions. Second, test 2 does not
> seem to be 
> influenced by the GTK+ version too much. Third, when I use
> slow fancy 
> themes in both GTK+ versions (Victory, Adwaita, New
> Wave...), I still 
> get the same pattern again - even though a fancy theme
> makes both 
> versions (sometimes even 6x) slower, 3.x is still 50-150%
> slower than 
> 2.x (except for test 2, which seems to be mainly influenced
> by the 
> theme itself). And fourth, even a slow fancy GTK+ 2.x theme
> is faster 
> than the plain default 3.x theme.
> 
> Finally, it's not my Linux distribution either. I ran the
> tests in 3 
> different distros (Arch Linux, LMDE and Fedora 15, with
> Xfce in all of 
> them), and always got similar results.
> 
> So my question is - is there something in GTK+ 3.0 that
> could possibly 
> cause such a dramatic slowdown compared to 2.24?
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> 

File a bug.

Regards,
  Sergei.