Lags in many apps (but not the others) when the GPU is 100% busy

Serge Rogatch

2/11/23, 11:32 AM

I'm using Ubuntu 20.04 (default desktop install, i.e. with Gnome I suppose) and NVIDIA GeForce RTX 2080 GPU. When the GPU is 100% busy with a background process, some apps start lagging. Namely, those are the apps that use non-OpenGL QT rendering (e.g. Telegram Desktop) or GTK/Gnome/Cairo (Sublime Text, Mozilla Firefox). The other apps like Chrome, Terminal, VS Code, and Slack do not lag. When I changed the rendering backend in Sublime Text from GTK/Gnome/Cairo to OpenGL, it stopped lagging too. The lagging appears as a slow UI (long response for switching tabs and windows or scrolling), and characters do not appear immediately as I type them in.

To reproduce this, you can:

Launch a GPU-intensive application in the background, such as Tensorflow or a crypto miner
Launch an app that uses QT (without OpenGL) or Cairo
Try to use the UI in the app

It seems not to be a problem of long CUDA kernels, as some apps work without lags in this setting.

Is there a configuration option to Xorg/Gnome/QT/GTK/Cairo that can help get rid of the lag?

I submitted a bug to one of the apps https://github.com/telegramdesktop/tdesktop/issues/17091 , but its maintainers suggest fixing the problem in the rendering libraries or the OS instead.

0 + 0

gnome

gtk

cairo

20.04

David

2/11/23, 11:43 AM

Your machine is busy it gets slow. Do not know of any setting is going to make it less busy.

Serge Rogatch

2/11/23, 11:57 AM

@David, but it is fine for some apps, but not the others. So it seems I just need to configure those specific rendering libraries.

Elon Musk

I sit in a Tesla and translated this thread with Ai:

EN: Lags in many apps (but not the others) when the GPU is 100% busy

TH: ล่าช้าในหลาย ๆ แอพ (แต่ไม่ใช่แอพอื่น ๆ ) เมื่อ GPU ไม่ว่าง 100%

RO: Întârzieri în multe aplicații (dar nu în celelalte) atunci când GPU-ul este ocupat 100%.

RU: Задержки во многих приложениях (но не в других), когда графический процессор загружен на 100%

VI: Độ trễ trong nhiều ứng dụng (chứ không phải những ứng dụng khác) khi GPU bận 100%

Post an answer

Most people don’t grasp that asking a lot of questions unlocks learning and improves interpersonal bonding. In Alison’s studies, for example, though people could accurately recall how many questions had been asked in their conversations, they didn’t intuit the link between questions and liking. Across four studies, in which participants were engaged in conversations themselves or read transcripts of others’ conversations, people tended not to realize that question asking would influence—or had influenced—the level of amity between the conversationalists.