Hi Daniel, The fix for this issue not only requires xorg 1.21.1.4, but also a newer version of the Nvidia driver. We have confirmed that the combination that fixes this issue is (1) xorg 1.21.1.4 (from Kinetic) + (2) a development version of the Nvidia driver, which is under NDA.
To be honest, Nvidia is also a black box for us. We don't know the root cause of the lag or whether it affects only the Nvidia-525. -- You received this bug notification because you are a member of Desktop Packages, which is subscribed to xorg-server in Ubuntu. https://bugs.launchpad.net/bugs/2009767 Title: external HDMI monitor is laggy on NV reverse PRIME system Status in OEM Priority Project: New Status in xorg-server package in Ubuntu: Confirmed Bug description: [Summary] When the graphic mode is on-demand mode and plug in the monitor to HDMI port, there are two issue occures: 1. External monitor's screen is very laggy in external monitor mode only. 2. External monitor's screen sometimes (~50%) will be blak in join display mode. [Steps to reproduce] 1. Boot in OS 2. Plug in the external monitor in HDMI port 3. Find the cursor moving in external monitor is laggy [Additional information] Feedback from NV: An NVIDIA driver built with the features needed to get rid of the laggy monitor problem causes Xorg 1.21.1.3 to crash. There's a patch for Xorg to fix the crash (https://gitlab.freedesktop.org/xorg/xserver/-/issues/1275) and it was first included in the 1.21.1.4 release. Since the older X servers crash, NVIDIA deliberately does a version check in the driver and enables these features for Xorg servers that are known to work, i.e. 1.21.1.4 or higher. This unfortunately prevents backporting the fix to 1.21.1.3. Engineering has chosen this approach since a crash is worse than the low FPS lag and the user might lose work merely by plugging/unplugging displays. If it was about a performance degradation, slight corruption, or something non-fatal, we wouldn't need to check Xorg version To manage notifications about this bug go to: https://bugs.launchpad.net/oem-priority/+bug/2009767/+subscriptions -- Mailing list: https://launchpad.net/~desktop-packages Post to : desktop-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~desktop-packages More help : https://help.launchpad.net/ListHelp
