Hi, > 2014-09-01 22:23 GMT+03:00 Rūdolfs Bundulis > <[email protected] <mailto:[email protected]>>: > > Hi, > > any hints on how to understand if a Windows 7 guest OS uses XPDM > or WDDM driver? I would be interrested to see if with XPDM I can > actually reduce the needed memory for the surfaces. >
Look at the guest Computer/Properties/Device Manager/Display Adapters/VirtualBox Graphics Adapter/Driver/Driver Details XPDM files are VBoxVideo.sys and VBoxDisp.dll XPDM requires less guest VRAM, it mostly needs VRAM for the screen surface. With 256MB of VRAM it is able to support 24 or 25 monitors at 1920x1200x32 each. One screen needs ~9MB, which gives a hard limit 256/9 ~= 28 screens. But since some VRAM is needed for other purposes, it is better not to use the maximum. The performance will be probably a bit worse compared to the case when each guest screen has enough VRAM for a full resolution offscreen surface. I just tested a VBoxHeadless VM with 24 monitors at 1920x1200 and 256 MB of guest VRAM and it seems to work fine. Vitali _______________________________________________ vbox-dev mailing list [email protected] https://www.virtualbox.org/mailman/listinfo/vbox-dev
