>Could you mail me the testcase. Feel free to send it privately if you >don't want to send to the mailing list.
This is not an independant test application. My stuff is too much intricated in my application to be extracted easily. But since graphics performance is important for my application, I might end up doing a test application to measure the performance of the Qt APIs I use under OSX , to know what to do to get the best performances. In which case I would send you that bench app. Philippe On Thu, 22 Oct 2009 09:02:01 +0200 Gunnar Sletta <[email protected]> wrote: > ext Philippe wrote: > > I have done some more rigorous benchmarking to better understand the > > graphics performance differences between OSX and Windows, and according > > to various methods. > > I have tested drawing using the raster engine or the native engine > > (on windows, it's the same), and drawing directly or indirectly > > via a QImage or QPixmap. This for both OSX and Windows. > Could you mail me the testcase. Feel free to send it privately if you > don't want to send to the mailing list. > > > > Figures follow. > > > > Tested with Qt 4.6 beta 1, on a quad-core i7 2.66 GHz (Mac Pro) > > with either OSX 10.5 or Windows 7 > > Time in milliseconds (smaller is better). > > A surface of about 2 millions pixels is painted, simple stuff, > > consisting of a gradient background, about 4000 lines, a bit of text. > > No anti-aliasing. > > Of course the figures could be very different with another graphics > > contents. > > > > Engine QImage QPixmap OSX Windows > > =========================================================== > > native 42 14 > > native yes 28 15 > > native yes 44 15 > > > > raster 30 14 > > raster yes 33 15 > > raster yes 34 15 > > > > What these figures show mainly is: > > > > * Drawing under Windows is between 2 and 3 times faster (!). > > > > * Raster engine is preferred on the mac, unless one draws > > into a QImage, which is then the best solution. > > I hope I can test soon on snow leopard to see if there is an improvement. > > > > The QImage speed suggests that drawing performance on OSX could be > > sensibly improved > > by using a better compiler. In Digital Signal Processing, > > it is not unusual to see a +100% speed improvement by using the intel > > compiler in certain parts, > > though this is never something systematic. This compiler is good but > > very slow to compile. > > Maybe the Qt drawing primitives could be isolated and compiled > > separatly using such compiler... > Much of the pixel-level code in the raster paint engine is assembly and > compiler tweaked C code... That is why I say that though there are > differences in the compilers, they don't show up as this kind of > different. I suspect that we are not properly hitting the SSE / MMX > paths for instance. > > - > Gunnar _______________________________________________ Qt4-preview-feedback mailing list [email protected] http://lists.trolltech.com/mailman/listinfo/qt4-preview-feedback
