Do I understand, then, that disabling Full Screen Optimization can impact performance when, say, capturing a session for movie making?
How about other 'background' processes, such as TrackIR?
Based on what I already understood, and then what I found in the link that Storebror posted, disabling FSO
might interfere with the performance of the video capture software a little. This biggest potential performance issues when disabling FSO (according to the article linked above) is for in-game overlays like Gamebar, the Steam Overlay, or (in my specific case) the AMD overlay that you can use to tweak graphics settings on the fly.
That said, after turning it on and off a few times while experimenting and "benchmarking"...and I use that term loooosely...it has no noticeable impact on game performance or background processes. It seems like bomberkiller's experience with his GTX 760 backs that up. The game is old enough that even "old" hardware can handle it easily and disabling FSO won't have any noticeable positive impact on the performance of the game.
The chief reason I was playing around with FSO to begin with was that I was trying to
limit my frame rate to cap out at the native refresh of my monitor. My card has some quite noticeable coil whine at stupid high frame rates, so the squealing I can hear through my headphones on the 1000fps menus is something I'd like to quash.
I think now that I might have fixed that issue with a driver update? Because I rolled back to 22.6.1 AMD for the sake of getting OpenGL to actually work, and now I'm having trouble corralling the frame rate the way I'd like to again.
AMD 5600X CPU, AMD 6900XT, 32GB of RAM, and Win10 Home, for reference.
At the end of the day: fiddle with it. It probably won't make any difference, but who knows? Maybe your video capture or TrackIR will benefit (or choke). Turning it on and off makes no permanent changes. Any change can be reversed by toggling it back to the other option.