It looks like problem appears only off steam games. What i mean is that its dropping FPS on desktop and in any other (non steam) fullscreen app like LoL. I assume its gnome3 + steam integration problem then. (when someone writes a message or you get any notification in right bottom corner of desktop you can see that it is coming out not smooth)
Is this only when you get notifications or also when you open the overlay by hand and no notifications are otherwise on screen?
I don't use the overlay in non-steam games therefore i can't open it.
It happens only when i get notifications.
OK, that makes sense. The NVIDIA driver is designed is such a way where X11 windows are manipulated, all OpenGL rendering will hitch. This causes the stuttering you're seeing when the Steam notification window is shown, because the GNOME compositing manager is OpenGL-based. A while back we filed issue 1519562 with them about this particular issue, which is now closes as "Will not fix". If you're inconvenienced by this issue on a regular basis I encourage you to notify them through their forums or switch to AMD or Intel graphics. Sorry I can't be of any more assistance with this as this is out of our control.
10 years later. same issue.
"nvidia, **** you"
-Linus
Very disheartening finding this conversation 10 years later. Very different OS (Arch [Garuda] - KDE - Wayland), but same issue.
Nothing extracted yet.
Specs:
Fedora 20 x64 + nvidia drivers (http://www.if-not-true-then-false.com/2014/fedora-20-nvidia-guide/)
Gnome3
GF 560 TI
i5 2500k
Reproduce - play ANY game (not only steam, league of legends for example), wait until someone writes to you or just steam overlay appears for some reason = FPS DROP (less than 30).
Same happens to the beta release of steam (with the new look).