[SOLVED] 12th Gen - External USB-C 4k monitor - Poor performance

Framework Laptop 13 Linux
1

I’m using a 4k monitor over usb-c with my 12th gen DIY edition, and Gentoo Linux.

I’m using the modesetting X11 driver with Glamor acceleration. Linux 6.1.10, with a hand-built kernel config.

Basically, graphics performance really lags when using this external monitor. Things like browsing the web. Graphics performance is snappy without the external monitor.

I don’t see any particular errors or warnings in dmesg or Xorg.0.log,

Any suggestions? Should I expect this to work better?

2

Hello,

you’re missing two critical pieces of information here:

  • Does this also happen on the stock kernel?
  • Where is your modified kernel config? Without there is nothing we can do to help you.
3

Here’s my kernel config: MicroBin

There isn’t really a stock kernel for this distro. Is there any recommended list of kernel modules/features for Framework laptops? I mostly worked off of the suggestions on this wiki page. then added things as I ran into them.

4

I have had similar experiences with a bad cord. Have you tried swapping it out…before you go down the software rabbit hole?

5

It’s probably running on 30Hz. For some reason that always lags, in my experience, even on dedicated cards on desktop.
Can you check? Perhaps try with the display port adapter or a different cable or something?
I haven’t managed to get 60fps over USB-C on my 4k screen either, but I rarely use it and never bothered to check what the problem is there, and yes, it lags on the laptop while only letting me choose 30Hz, and if I explicitly choose 30 on the desktop it also lags behind but is perfectly fine on 60.

6

I’d check the following:

  • Refresh rate, is it set correctly?
  • This is a direct connection (no docks or adapters) to the display?
  • I’d test this with Display Port or HDMI for a better experience. I’ve used USB-C successfully in the past, but it can be hit and miss.
7

Sorry, took a while to get a DP adapter.

  • Both DP and USB-C seem to be running at 60hz and perform similarly.
  • No docks or adapters
  • Tried another cable without change

I did get some performance benefit in chrome by setting up VA-API but overall performance remains poor

8

Let’s start off with the output of xrandr. Also, what types of performance issues are you experiencing?

  • Which are applications are open?
  • Which specific changes made?
  • What type of lag are you experiencing?
9

Sorry for the slow responses.

After some debugging … it turns out that I was having an issue with excessive CPU throttling that was fixed with the 3.0.6 BIOS update ([IN-TICKET] 12th gen - excessive CPU throttling on Linux - Can't get above 46c and pegs to 400mhz under load - #2 by NegatedVoid).

Now, the 4k external over usb-c … is working great. I guess powering the larger resolution just tended to push the mainboard harder and it was probably throttling inappropriately.

4 Likes
10

Delighted this has been resolved with the update! :slight_smile: Thanks for the update.