Better performances in desktop mode ?

[Spychopat]

Sometime i play on an external monitor.
I used to do it in game mode for better performances, but lately i tried to play in desktop mode because i wanted to tweak gamma and have access to a browser + discord.
And... to my surprise, it seems the performances are much better ?
Maybe i'm imagining things, but for example on desktop mode i have a solid non stop 60fps on dead by daylight, but in game mode it's sometime lower.

Am i crazy ? Or maybe there was updates that increased performances ?

[Haruspex]

There shouldn't be a difference. Have you set a custom game profile with lower clock settings or a framerate limit and forgot about it? I'm not sure if those kick in on desktop mode.

[Spychopat]

Originally posted by Haruspex:

There shouldn't be a difference. Have you set a custom game profile with lower clock settings or a framerate limit and forgot about it? I'm not sure if those kick in on desktop mode.

Well, even without TDP limit, the game struggled a bit in game mode. Now i play with a TDP limit to avoid heating and fan noise (for pretty much the same performances). But it seems to carry over desktop mode anyway, because the fan is still silent.
Maybe it's because of the anti cheat ? It doesn't like being in gamescope ?

[Spychopat]

I'll try again in gamemode later, maybe there was an update, but would be crazy that an update increased performances so much. I remember that it was not much enjoyable because of performances, but now it's seemless.

[WarnerCK]

The two performance differences between the two modes that I'm aware of are vthat desktop mode has a desktop environment loaded, whereas gaming mode doesn't, and gaming mode pretends that the number of threads is the number of cores, whereas desktop mode more accurately reports the number of cores and the number of threads. Each of those should make either zero difference, or marginal difference in favour of gaming mode. But quirks are always possible.

It could have just been an update that improved performance since the last time you played in gaming mode.

[Spychopat]

I just tried a game in game mode.
In fact, the framerate is always showing really high, but i notice like very small stutters, and less smooth gameplay. I can't measure it, it's just a feeling, but maybe i'm crazy xD

Oh, and i confirm that TDP limit carries over desktop mode. I turned it off, and now in desktop mode my fans are going crazy.

[Spychopat]

Also, i'm playing on an external monitor, maybe it's using it better in desktop mode ? i'm locking framerate at 60, but the monitor is 75hz

[thetargos]

It makes sense in that Gaming mode uses Wayland and Gamescope, and Desktop mode uses X11 (and the kwin compositor). The vast majority of games (there are a few games that actually make use of Wayland directly now) run under XWayland, an X11 abstraction over Wayland (not a compatibility layer, but rather X11 protocol implementation under Wayland), which results in performance hit. The same happens when you run a Wayland application over a nested X11 environment.

[Spychopat]

Originally posted by thetargos:

It makes sense in that Gaming mode uses Wayland and Gamescope, and Desktop mode uses X11 (and the kwin compositor). The vast majority of games (there are a few games that actually make use of Wayland directly now) run under XWayland, an X11 abstraction over Wayland (not a compatibility layer, but rather X11 protocol implementation under Wayland), which results in performance hit. The same happens when you run a Wayland application over a nested X11 environment.

So, you mean that gaming mode is using an extra layer, and that may impact performances in games ? Why is it done this way then ?

[thetargos]

Originally posted by Spychopat:

So, you mean that gaming mode is using an extra layer, and that may impact performances in games ? Why is it done this way then ?

It is a tradeoff. Despite it being a Wayland compositor, Gamescope is faster than kwin, weston and Mutter when handling XWayland clients. Though, given its inner workings, it still is not fully compatible with nvidia (either one will have to yield, nvidia fully supporting the Wayland way, or Valve having to code a bunch of alternate ways to perform the same with mesa and the nvidia driver).

For the most part, Gamescope allows for most of gaming mode's features, so it is not all that bad, and the performance hit from XWayland typically (in oder words, not always) is within negligible margins (1~2%), alas some apps suffer more than others.

[Prometheus]

I play a game called 4 Kings Casino, and I can tell you, using an external monitor/tv @1080x1920, the quality is much better in desktop mode than in gaming mode. In fact, I now only play the game in desktop mode, but it does tax the hardware since I have the quality settings within the game maxed out. In other words, from my experience, the game video quality is just as good as the Xbox X or PS5 in Desktop mode compared to Gaming mode which gives about the same resolution quality as a PS4 or Xbox One. Not sure about framerates, etc. Just details such as text, background, character definition.

[thetargos]

That would not be surprising, given, most likely the game in Gaming mode runs at the native 800p resolution, rather than the higher resolution of 1080p, which might be what you are perceiving as better in terms of quality, despite the game rendering at the same "quality settings" within its options.