hybr wrote: > Hi, David, > > 4xx series slow specifically on readback from framebuffer\FBO to > texture\PBO\host memory (in GL, dunno about cuda\opencl). That is what all > people talking about. If you dont use this features much you will have no > problems whatsoever. > > Cheers, Sergey. > > 19.05.2011, 03:27, "David Glenn" <>: > > > Jason Daly wrote: > > > > > > > On 05/18/2011 05:14 AM, Fred Smith wrote: > > > > > > > Hi, > > > > > > > > The only problem that I personally heard about is about the slow > > > > transfer speed to/from GPU memory on Fermi cards. DMA transfers are > > > > said to be slower than on GTX 2xx hardware. I haven't seen anything > > > > related to computing. > > > > > > > I think it's specifically GPU->host memory transfers that are slow. The > > > other direction is OK, as is the computation speed. The thread on the > > > OpenGL forums has the details, and someone posted a small program that > > > does timing tests and illustrates the issue pretty well. > > > > > > http://www.opengl.org/discussion_boards/ubbthreads.php?ubb=showflat&Number=284065&page=1 > > > > > > --"J" > > > > > > > I looked at the link you gave and downloaded the program that was the (the > > 4th revision of it) and tried on my GTX 460 and an old 8800 GT and compared > > it to the results that was posted and something does not add up with the > > test program! > > > > Before I learned of all of this, I ran some other tests using a stress > > program and gDEBugger and found that the GTX 460 was much faster than 8800 > > GT (about 10 times faster under stress). I also tested it on most of my > > high end terrain and it ran much faster (about the biggest texture based > > thing I have) even though I don't have figures for it yet. > > > > I'm not saying that there is not a problem, but I'm a bit confused when one > > test I do contadicted by another and that the numbers for that other test > > and the conclusion seem spect to me! > > > > D Glenn > > > > ------------------------ > > D Glenn (a.k.a David Glenn) - Moving Heaven and Earth! > > > > ------------------ > > Read this topic online here: > > http://forum.openscenegraph.org/viewtopic.php?p=39519#39519 > > > > _______________________________________________ > > osg-users mailing list > > > > http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org > > > _______________________________________________ > osg-users mailing list > > http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org > > ------------------ > Post generated by Mail2Forum
Well I'm using a far chunk of terrain that is very texture based and I haven't seen any issues. Maybe I'm making a mistake getting the 460's and sould try the GTX 280. ------------------------ D Glenn (a.k.a David Glenn) - Moving Heaven and Earth! ------------------ Read this topic online here: http://forum.openscenegraph.org/viewtopic.php?p=39561#39561 _______________________________________________ osg-users mailing list [email protected] http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
