I5-7300u constant 100% at 4k (Ubuntu 18.04)

Software & Operating Systems Linux
1

Hi, so I’ve got a Dell laptop with an i5-7300u. I’ve recently upgraded to a 4k monitor at home that I plan on using for video playback and programming (i have a desktop PC for gaming).

Now, according to Intel’s website and other platforms (youtube guides, web articles, etc), the i5 should be able to handle 4k video, etc. It’s alright with general tasks (I’m writing this on the 4k monitor just now). But as soon as I put youtube on at 1080p/4k the CPU hits 100% and stutters like mad. I’m not sure if this is a Ubuntu issue, browser issue or if my CPU just isn’t meant for 4k despite Intel saying it is.

Any advice would be great, sorry if the post is too long I tried to fit as much information in as I could.

2

Before digging in too deeply I’d start off by testing if there’s any difference between uxa or sna in the graphics conf.

https://wiki.archlinux.org/index.php/Intel_graphics#Troubleshooting

3

Thanks for the link, I couldn’t find the config file (/etc/X11/xorg.conf.d/20-intel.conf) on my system though?

4

Depending on your distro the conf file might be in a different directory.
It should be under /etc/X11 - but if it ain’t, create a conf file in /etc/X11/xorg.conf.d/

5

What browser? should have hardware decoding so if hardware accel isnt enabled, thats likely the issue.

6

Chrome, hardware encoding is enabled already.

7

I couldn’t see anything like xorg in the X11 directory. I’ll check the docs again and try and create one.

8

Check the paragraph here:
https://wiki.archlinux.org/index.php/Intel_graphics#Xorg_configuration

There’s also a link to the intel man page, but long stoey short you should add

“Option” “AccelMethod” “uxa”

To your file to change from sna to uxa.

But again, I’m not sure if it’ll fix the issue, but worth trying out.

Edit: don’t copy and paste what I posted, I might have typoed. On phone, writing from memory.

9

Is the monitor running at 60hz? My T580 stutters badly with YouTube at 4k, even though it has an i7 and it’s not hitting CPU limits (though it’s more usage than I would expect at 4k), because it is running at 30hz over the HDMI. (Both monitor and laptop, a Lenovo T580, are HDMI 1.4)

No problem with 4k YouTube on DisplayPort over USB-C, since that runs at 60hz.

10

Sorry should’ve updated this. It’s definitely a Linux/Ubuntu issue. I’ve started using windows again on the laptop and it runs fine at 4k. Would like to go back to Linux so I’ll be messing about with it soon.