Hi Top posting here to pick up the original thread:
Radim you mentioned QPixmap vs QImage. I was looking at why one of the unit tests is doing wierd rendering today and happened to read this: "Performance QPainter is a rich framework that allows developers to do a great variety of graphical operations, such as gradients, composition modes and vector graphics. And QPainter can do this across a variety of different hardware and software stacks. Naturally the underlying combination of hardware and software has some implications for performance, and ensuring that every single operation is fast in combination with all the various combinations of composition modes, brushes, clipping, transformation, etc, is close to an impossible task because of the number of permutations. As a compromise we have selected a subset of the QPainter API and backends, where performance is guaranteed to be as good as we can sensibly get it for the given combination of hardware and software. The backends we focus on as high-performance engines are: Raster - This backend implements all rendering in pure software and is always used to render into QImages. For optimal performance only use the format types QImage::Format_ARGB32_Premultiplied, QImage::Format_RGB32 or QImage::Format_RGB16. Any other format, including QImage::Format_ARGB32, has significantly worse performance. This engine is also used by default on Windows and on QWS. It can be used as default graphics system on any OS/hardware/software combination by passing -graphicssystem raster on the command line OpenGL 2.0 (ES) - This backend is the primary backend for hardware accelerated graphics. It can be run on desktop machines and embedded devices supporting the OpenGL 2.0 or OpenGL/ES 2.0 specification. This includes most graphics chips produced in the last couple of years. The engine can be enabled by using QPainter onto a QGLWidget or by passing -graphicssystem opengl on the command line when the underlying system supports it. OpenVG - This backend implements the Khronos standard for 2D and Vector Graphics. It is primarily for embedded devices with hardware support for OpenVG. The engine can be enabled by passing -graphicssystem openvg on the command line when the underlying system supports it." Currently we are using: gui/qgsmapcanvasmap.cpp: mImage = QImage( size, QImage::Format_RGB32 ) Which is good as far as using the Raster backend, but maybe there will be some performance gain from using opengl where the processing can be done on the graphics card? Regards Tim On Sun, Apr 8, 2012 at 12:01 PM, Tim Sutton <[email protected]> wrote: > Hi > > On Sat, Apr 7, 2012 at 9:08 AM, Paolo Cavallini <[email protected]> wrote: >> Il 06/04/2012 13:00, Radim Blazek ha scritto: >> >>> To get comparable results, the benchmark must be run on a computer >>> with no or little other load (Linux kernel counts process switching >>> overhead in process time) and CPU parameters must not change >>> frequently (all the data collected are relative). >>> >>> The requirement would be a dedicated time (1-2h per day should be >>> sufficient) on a server with 2 CPU/cores (the second for database in >>> case of db providers). >> >> So, it may be better to have a dedicated virtual server for this? >> >> BTW: can we have an overview of the "qgis servers"? How many, which >> services, who is root on which? I think if we need additional resources (as >> this thread implies), we can plan for a consolidation & upgrade, and search >> ad hoc funding for this. >> Thanks. >> > > This is the type of info that needs to go in the QGIS -Governance > docs. But due to all the consolidation work there is only now: > > - qgis.org server hosted by OSGEO > - android.qgis.org hosting donated by me > > Gary and I used to run much of the project infrastructure on our own > servers but that has pretty much all been rationalised to the servers > above now. Possibly we could ask OSGEO for another vm if needed. We > could also build benchmarks on my server, but it wouldnt be a zero > load environment as Radim suggested. > > Regards > > Tim > > >> >> -- >> Paolo Cavallini >> See: http://www.faunalia.it/pc >> >> _______________________________________________ >> Qgis-developer mailing list >> [email protected] >> http://lists.osgeo.org/mailman/listinfo/qgis-developer > > > > -- > Tim Sutton - QGIS Project Steering Committee Member (Release Manager) > ============================================== > Please do not email me off-list with technical > support questions. Using the lists will gain > more exposure for your issues and the knowledge > surrounding your issue will be shared with all. > > Visit http://linfiniti.com to find out about: > * QGIS programming and support services > * Mapserver and PostGIS based hosting plans > * FOSS Consulting Services > Skype: timlinux > Irc: timlinux on #qgis at freenode.net > ============================================== -- Tim Sutton - QGIS Project Steering Committee Member (Release Manager) ============================================== Please do not email me off-list with technical support questions. Using the lists will gain more exposure for your issues and the knowledge surrounding your issue will be shared with all. Visit http://linfiniti.com to find out about: * QGIS programming and support services * Mapserver and PostGIS based hosting plans * FOSS Consulting Services Skype: timlinux Irc: timlinux on #qgis at freenode.net ============================================== _______________________________________________ Qgis-developer mailing list [email protected] http://lists.osgeo.org/mailman/listinfo/qgis-developer
