Hi Joe, With the cull and draw going sky high it very much looks a driver bug to me.
In my own PC based mutli-GPU testing I've found that serializing the draw dispatch helped performance, so made this the default but you can override this using the env var: OSG_SERIALIZE_DRAW_DISPATCH set to OFF. A couple of days ago I did try to set up my new Core i7/X58 system up with two graphics cards but the kernel/NVidia drivers couldn't initialize themselves properly so I wasn't able to boot. I was just using the NVidia driver pulled down for Ubuntu repositories so this might be part of the problem, or it could be that I have see a bleeding edge hardware setup that the kernel/drivers haven't caught up yet. Frustratingly this system hardware wise is most capable of doing scalable multi-GPU work, but right now I don't have the time to go routing around for a solution so can't test multi-gpu setups right away. My previous workstation also supported dual GPU but a broken disk on it means that right now I'm just working on my new machine and without the ability to test dual GPU. Robert. On Fri, Oct 31, 2008 at 4:16 PM, Joe Lyga <jdl...@gmail.com> wrote: > Hi osg-users, > > I'm having another issue with my four monitor setup with 2 graphics > cards. Now that I'm running Windows XP, I'm past the OS/Driver issue > that was slowing down both osg-viewer and my program when it was being > displayed in one graphics context across all four monitors. However, > now I'm having a problem when trying to run with more than one > graphics context. > > My machine is running Windows XP that has two Geforce 8800 GTX > graphics cards. I'm running these cards with SLI disabled so I can > hook up 4 monitors, with 2 on each graphics card. I have my 4 > monitors aligned side by side in display properties, each set to 1400 > x 1050 resolution. I have vsync turned off. > > Anyway, when I'm running in one 5600 x 1050 graphics context (which is > across all four monitors), I'm getting around 140 frames per second > <see first screenshot>. > > If I switch it so there are two 2800 x 1050 graphics contexts, the > performance drops to around 14 frames per second. Also, the draw and > gpu reads almost 10 times what it did with a single context <see > second screenshot>. > > Does anyone have any insight on why two graphics contexts would be > slowing down my program? > > _______________________________________________ > osg-users mailing list > osg-users@lists.openscenegraph.org > http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org > > _______________________________________________ osg-users mailing list osg-users@lists.openscenegraph.org http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
