Low UI FPS, pi4?

Hi all

Is it normal to be getting 10-15 fps navigating the UI on a pi4? Everything else works fine, watching 60fps videos at 4k and stuff, but the debugging is reporting very low FPS.

I just upgraded from a pi3 in a smaller 1080p tv to a pi4 on a 4k tv and I’m not sure I quite remember the UI having such a low fps or not on the pi3. I don’t have that old telly anymore so I can’t double check.

I’m running rbp4-mediacenter-osmc 19.5.0


Yes, that’s normal for this platform.

Are you actually seeing latency when using the UI or are you just concerned by the FPS count?

I would say yeah, I am experiencing a tiny bit of latency and the UI can feel a tad laggy sometimes especially on large UI transitions, but never enough to investigate.

The reason I noticed the low fps though was because I had the debug menu on trying to make Kodi work properly with my remote via hdmicec - my new tv sends different “commands” for the return and exit remote buttons than my old one did, and I was trying to restore “return” to Context menu and “exit” to Back I think.
While debugging the hdmicec I noticed the fps dropping to as low as 9fps on some occasions on large UI transitions and thought “oh that’s why it might feel a bit jittery or laggy sometimes”

Is there a way to increase the fps or a reason it needs to be low?

Edit: to be clear, if I’ve got a screen full of videos and I’m just moving around them, that doesn’t feel laggy. It feels fine. Just the UI feels laggy transitioning between pages sometimes.

sometime also on my pi2 the ui appears to be lagged… i ever thinks it’s limit of my old pi2 or it’s caused by my lg tv remote when i use the CEC…

What is actually the GUI resolution you have configured?

4096x2160 which doesn’t seem right because my tv is a 4k tv and 4k is 3840x2160

I changed it to 3840, no difference. I’m not too worried about it.

We recommend people with 4K TVs set their user interface (UI) to 1080p. Kodi’s UI is not optimized for 4K yet and this can put unnecessary demands on your device and can lead to a suboptimal picture quality, as well as potentially cause other issues.

The settings we recommend are as follows…

Settings>System>Display>Resolution> 1920x1080p
Settings>System>Display>Whitelist> (empty) *
Settings>Player>Videos>Adjust display refresh rate>Always

Some televisions may also need, or benefit from, the following being set…

System>Display>Force 4:2:2 colour subsampling> (enable)

With the above settings your UI will be output in Full HD and your 4K content will be output in 4K.

*Information regarding the whitelist can be found here. If you have any doubt, feel free to upload some logs so we can verify that your settings are indeed correct.

Sweetbix I’ll give it a shot!

Oh wow @fzinken - thanks for the tips, the difference is night and day!

Like I said before, the video always played fine so I wasn’t too bothered but now that I’ve changed it to the settings you mentioned the UI feels very very much nicer. When I put the debug logging on, I can see the fps jump up from 9/10 fps to above thirty and large transitions are much smoother - but also just navigation in general is as well.

Specifically I changed

Settings>System>Display>Resolution> From 3840x2160 to 1920x1080p

Settings>Player>Videos>Adjust display refresh rate> from on start stop to Always

While for this setting
Settings>System>Display>Whitelist> (empty) *

I didn’t know what you meant by (empty) * but I left it default - a huge list of all sorts of resolutions, and the resolution does switch upon playing 4k content, my tv confirms it.

As for
System>Display>Force 4:2:2 colour subsampling> (enable)

I can’t find that setting, but everything seems to look right, so, cool I guess :slight_smile:

It’s funny, I almost didn’t ask. Glad I did. Thanks again! I got my remote problem fixed as well, after a tedious few minutes in the keymap plugin.

That’s the important one.

Most of the time that makes no difference. The only time it does is if you bring up the UI during playback - with the setting set to Always, you will get a mode switch (and your screen will go back for a couple of seconds); the same will happen when you go out of the UI and back to the video. On start/stop only changes mode at the when you start or stop the video playing.

Setting that to Off will cause all kinds of problems, though, so don’t do that!

By default, there are no resolutions whitelisted (which is probably what you’ve got).

fzinken already gave you this link, but if you want to know more about the whitelist then I suggest you click here.

Maybe you don’t have Settings Level set to Expert?

But in any case, you only need that setting if your OSMC device is struggling to establish or maintain a stable HDMI connection with the display.

This setting is only visible for Vero users.