On 8 May 2017 12:10:13 a.m. GMT+02:00, Ben Skeggs <[email protected]> wrote: >On 05/07/2017 11:12 PM, Ilia Mirkin wrote: >> On Sun, May 7, 2017 at 7:17 AM, Sampsa Riikonen ><[email protected]> wrote: >>> Dear Devs, >>> >>> We have achieved a desktop of up to six monitors, with openGL >running >>> succesfully on the desktop, with the following setup/features: >>> >>> * Ubuntu 16+ >>> * Xrandr >>> * Noveau driver >>> * Two gtx750 graphic cards >>> >>> Each (identical) graphic card has 2xHDMI + 2xDVI connectors, which >we >>> connect to the monitor array. >>> >>> So far it works with six monitors, but we'd like to achieve eight. >>> However, throwing in more monitors, results in monitors starting to >drop >>> out (black screen). However, xrandr sees them correctly. >>> >>> The nv$dia proprietary driver is not an option - they have >artificially >>> restricted the amount of monitors in the "base mosaic" feature (ref. >>> >https://www.phoronix.com/forums/forum/linux-graphics-x-org-drivers/x-org-drm/46705-linux-multi-head-success-with-8-monitors-in-1-x-screen-without-xinerama >>> ). >>> >>> What might cause the monitors to drop out? I can provide some logs >>> later next week (which file should I look at?) >>> >>> Could using nv$dia's proprietary firmware in noveau help? >>> >>> Regards, >>> >>> Sampsa >>> >>> P.S. This seems to be a bit outdated.. ? >>> >>> https://nouveau.freedesktop.org/wiki/MultiMonitorDesktop/ >>> >>> .. it implies that xinerama must be used to combine screens from two >>> different graphics cards into a single screen which implies that >opengl >>> should not work, right? >> >> Using reverse prime with a ton of screens has had a questionable >> success rate. Using Xinerama Just Works (tm). But you do lose direct >> rendering (but you still get OpenGL via indirect GLX, assuming the X >> server has that enabled). However in the past, this hasn't been an >> issue for the people trying to create such arrangements. >> >> With reverse prime, I believe it's all just one big framebuffer, so >> you run into fb size limits. I think we restrict it to 16k x 16k in >> size. >Another possibility is running into memory bandwidth limitations. >
And PCIe bandwidth, especially if only on 2.5 GT/s speed. So if this is done through Reverse Prime, reclocking is a must. >> >> Cheers, >> >> -ilia >> _______________________________________________ >> Nouveau mailing list >> [email protected] >> https://lists.freedesktop.org/mailman/listinfo/nouveau >> >_______________________________________________ >Nouveau mailing list >[email protected] >https://lists.freedesktop.org/mailman/listinfo/nouveau _______________________________________________ Nouveau mailing list [email protected] https://lists.freedesktop.org/mailman/listinfo/nouveau
