I’m running Fedora 43 on KDE (Wayland, I believe) with an AMD graphics card; I noticed a peculiarity with full-screen games that I hope someone can explain/solve?
For full-screen applications running on Steam (so I believe they are on their own compositors), I can be playing games with the graphics card running at what sounds like a low-medium load (graphics card fans are only on intermittently). The moment I Alt+Tab to the desktop (to check a file or look at a browser), the graphics card fans seem to go full tilt until I Alt+Tab back into my game. I.e. the fans suddenly spin up and temperatures start increasing.
When I look in `btop`, I can see that for the period where I am looking at my desktop (with the game running in the background), the graphics card appear to be under full load, but is at a lower load when I’m gaming. What could be causing this? (N.B. this is with stock settings.)
Just yesterday, I was playing with LACT to do some light undervolting (negative voltage offset) and power limiting. When I have a negative offset and power limit applied, the games run cooler and quieter than at stock (with a small performance penalty), but interestingly it makes the Alt+Tab issue worse (relatively speaking). Looking at the LACT power and fan plots, I can see that during gaming, power, fan speed, and thermals are under control and the card is not near maximum load at all. The moment I Alt+Tab to the desktop, again the power draw immediately shoots to to the power limit, fan starts screaming away (even harder than at stock settings), and temps start climbing. Until I go back to my game where it calms down again…
On exiting the game, the card seems to return to idle and doesn’t display the ramp up behaviour. It’s only when I’ve got the games running in the background.
Could this be something to do with frame limiting when a game is active on full screen, which gets it limit released in the background or something? I heard that by default, Wayland full-screens are essentially always vsync’ed, and therefore frame limited (if I understood that correctly). It would be nice to tab out to the desktop occasionally without the graphics card suddenly giving it everything is got while I stare at the desktop…
P.S. A quick shout-out to the helpful members who responded in this thread! I appreciated the advice but didn’t get around to replying (and don’t know if the thread is too old to say thanks there). I ended up getting the 9070XT, and it was great fun building my first system! If people are interested, I can post the specs later.