I'll try it today. It's very possible although I don't think it's the actual problem
Athlon II X2 250
4GB DDR3 1600
9800GT
The drop only happens when the overlay is visible, or does it stay after you've closed the overlay? It's expected that FPS will drop, possibly substantially, with the overlay open.
The drop is something like 300fps -> 80fps every time anyone sends me a message (and the 'you have a message' box comes up), and this does for whatever reason show as a slight freeze frame in the game. After I disabled these messages, I still occasionally get the very same fps drop. However I'm certain that the drop always happened during overlay graphics popping up on my screen, so I think it could be something with the steam in-game as well. Whenever i actually open the overlay to respond to messages etc, I experience some input delay and fps in the background game is always less than 20, unlike in windows.
The input delay and 10-15 fps while typing doesn't really bother me, but the jitter does. And I have no idea what could be causing it. I could mention though, that this drop and the jitter doesn't happen in any specific situation in the game, such as rocket being shot at me or anything, it always happens seemingly randomly.
You can turn off the overlay in the game properties. That will at least let you determine whether it's from the overlay or something in the game itself.
I turned off the overlay and steam community in-game and just about everything there was to turn off, still happens. Seems to happen more frequently with fps_max, or maybe that's just an illusion - it happens without it too. Also noticed the drop can be to a value as low as 60 too. Still couldn't find out anything specific that would trigger the drop, 10 rockets flying can go without affecting FPS at all and then suddenly walking around a corner with nobody around can cause it.
Looks like I forgot to mention I'm using Mint 14, KDE
Ubuntu 12.04, same here.
Closing as general video driver performance from 2013 is no longer relevant.
Nothing extracted yet.
Experiencing fps drops which show as slight jitter. Fps drop always when any graphics of steam overlay come to the screen (not talking about a small fps drop, fps literally at least halves). Also, possibly some other random fps drops that show as jitter - i'm not entirely certain if all of it is related to steam ingame.
Intel i7-2600 3.4ghz
AMD Radeon HD 6870
8GB Ram