Classification: UNCLASSIFIED Caveats: FOUO Nvidia chips use a very long pipeline and the GPU's like processing data. When they are not processing data they have a hard time performing. In order to keep the performance up, NVIDIA introduces the 2 frames latency to keep the pipeline full. Most likely the 40ms of retard you are noticing is your 2 frames latency. You will probably only notice the 2 frame latency when it is vsync'ed. When you are not vsync'ed you will get the tearing but you are also running faster than the sync rate and probably won't notice that built-in latency.
Hope that helps... -----Original Message----- From: osg-users-boun...@lists.openscenegraph.org [mailto:osg-users-boun...@lists.openscenegraph.org] On Behalf Of Giovanni Ferrari Sent: Thursday, June 24, 2010 1:04 AM To: osg-users@lists.openscenegraph.org Subject: Re: [osg-users] OSG and vsync Thank you very much for your reply ! I understand your suggestion about using external syncs to run at a multiple of the frame rate but i i don't understand the built in 2 frames of latency in Nvidia cards. I tell you this cause i used my system both with and without vsync and i noticed than running with vsync i don't have tearing but i measure extra 40ms of retard in the total closed loop respect to the free run case (no vsync). (with total closed loop i mean image rendering time + transmission time + elaboration of frame time + results_time) ------------------ Read this topic online here: http://forum.openscenegraph.org/viewtopic.php?p=29347#29347 _______________________________________________ osg-users mailing list osg-users@lists.openscenegraph.org http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.or g Classification: UNCLASSIFIED Caveats: FOUO _______________________________________________ osg-users mailing list osg-users@lists.openscenegraph.org http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
