13 Feb
2012
13 Feb
'12
8:50 p.m.
On Sunday 12 February 2012 02:20:38 Timothy Pearson
wrote:
I do not have any benchmarks handy at the moment, although this is simply
due to the length of time from those tests to the writing of this message.
The upshot was that Qt4 is significantly slower when it comes to
rendering raster graphics (as you mentioned), and also when large numbers
of widgets are displayed on-screen. If I understand some of the Qt
changes, the raster performance was improved somewhat in the latest
versions of Qt4, but I don't know if the other problems were addressed.
As an aside, 3D graphics hardware is not only expensive, it is also one of
the most proprietary and least-understood components in a typical computer
(it also tends to burn out a lot, at least that is my experience with
anything other than an enterprise-grade nVidia Quadro card). If nVidia
and ATI experienced supply shortages (don't laugh, remember the recent
hard drive scarcity due to flooding in Thailand) I would still need to be
able to use my computers with not-so-great backup graphics hardware, and
possibly without good OpenGL support.
More practically, even slightly sluggish performance is quite noticeable
to power users. Many applications, upon converting from Qt3 to Qt4,
appeared to slow down noticeably.
These are just my $0.02 and experiences in working with Qt 4.7. I am open
to looking at Qt4 again once Trolltech fixes the raster graphics problem
for good.
Tim
These are the exact reasons I stopped to the move
to Qt4 and picked up
maintinance of Qt3 (now becoming TQt3). I gave the conversion effort my
best shot (which took many, many months of effort) and stopped once it
became apparent how extensive Qt4's limitations were (especially in
drawing operations and native X11 window handling) and also how buggy
Qt4
really is.
May I ask for the benchmarking results? I am seriously interested here
as
I
think that I can provide you some valuable help here. My fear is that you
had
an incorrect benchmark (the experts call that phoronixing) and that your
decision is because of that on false grounds.
Especially important is to consider that graphics cards, drivers, what you
render (widgets vs scenes), which Qt graphicssystem you use seriously
influences the result. E.g. rendering widgets with raster might be a bad
idea.
Cheers
Martin