Unsolved
7 Posts
1
3406
Ubuntu external display extreme lags
Just bought Dell latitude 5421 i7-11850h MX450
Ubuntu 21.10 all drivers installed, even display link.
I have connected 4k60 external display via HDMI. to type-c adapter or directly to HDMI port of laptop.
Only external display is used.
Most of time it is OK but at some time it starts work like 2 FPS. If i switch to laptop's display - everything ok.
If back to external - the same lags. After a while lags stoping.
Is i scroll huge webpage while lagging i see how HTHL elements are rendering and the y appears very slow while scrolling page, even just cursor on desktop moves with lags.
syslog have no any interesting logs, nvidia-settings is switched to performance (MX450)
I dont want to return laptop back because i like it but it is completely impossible to work on.
While lags - CPU is not loaded (1-5%) ram is almost empty. i am working with AC.
it is pretty expensive laptop, i dont want to buy macbook, i want to keep linux. but my previous laptop works better because have no lags i5-8265U
proprietarilyfubar
6 Posts
0
December 16th, 2021 04:00
Hi there. I have exactly the same issue. I am using a Dell Precision 7560 (/w RTX A3000), Kubuntu 20.04, nvidia-drivers 470. Internal screen works perfect. As soon as I attach an external screen, it's suuuuuuuuuper slow.
errogaht
7 Posts
1
December 16th, 2021 04:00
intel 11th bug https://github.com/intel/thermal_daemon/issues/293
https://github.com/erpalma/throttled/issues/255
they dont want to solve it. it is intel 11th issue, dell don't want to fix. i've returned laptop back to seller. So recommend for you.
CPU throttling...
proprietarilyfubar
6 Posts
0
December 16th, 2021 07:00
@errogaht it seems the issue just got fixed after a firmware update. External + internal (or just external display) working like a charm now!!!
It's another topic (I think), however in regards what you were writing earlier on: I haven't noticed the throttling yet. But I've noticed their is an option in the Bios for somehow managing the performance. Again I haven't tried it out yet. But I will update you as soon as I fire up the GPUs for some machine learning and/or gaming.
Best ragards,
Sir Proprietarily FUBAR.
errogaht
7 Posts
0
December 16th, 2021 08:00
May be your issue is fixed but not mine and many others (CPU throttling to 400/800 Mhz in Linux)
I hope yours is fixed.
I thought it was something with video adapter, but when i was attaching 4k display my CPU usage was increased and after a while CPU was throttled to level of Intel Pentium 3 800. So lags were. At the moment f this topic creation a was still not able to figure out what is going on, but later i did understand.