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" <[email protected]>: > 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 > [email protected] > http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org _______________________________________________ osg-users mailing list [email protected] http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
