Graphics Settings & Overall game smoothness

[Franck83]

Hi,

Does graphics settings from individual players impacts global smoothness of a multiplayer game ?

I just played a game with 0 sim speed but some complains about lack of smoothness.

[JoonasTo]

Yes
Depending on their setup it may even affect others if their cpu starts bottlenecking the game.
Fa runs two heavy main threads: simulation and render. Aside from those there are a bunch of other threads, sound being most prominent, because of it’s nature. Now if the sim thread hogs all the cpu time there won’t be enough for the others and the render thread will struggle each time another thread wants cpu time(such as sound.) This will manifest as choppiness.

Worst case scenario the user is too heavily loaded that his game can’t keep up the network traffic properly(usually also involves priority problems.) This will mean tha game will lag for everyone involved, even if his connection is fine.

[speed2]

Only if someone plays on a single core CPU

[JoonasTo]

Incorrect.
Windows scheduling is shit. Fa scheduling is worse.
You can have 16 cores and Fa will happily wait on all of them at the same time. It is less likely to happen, not impossible. I, for example, am on an 8 core and if I don’t force anything most windows stuff and interrupts go to core 0. Fa will also happily priorize the same core for all it’s threads and wait on it first. This is why force disabling core 0 and forcing Fa threads to different cores actually improves performance, even if you’re technically limiting computing power. Fa threads are all linearly dependent so cpu output is less important than latency.

[speed2]

it wont run both ren and sim on the same core

[JoonasTo]

Try it. Windows scheduling doesn’t care.
It will put them to wait on any core it fancies, usually that ends up going from 0 to F and the first one that’s ready gets it. It doesn’t lock threads to cores. They jump around as they like. So at some points ren and sim do end up on the same core. Forcing them on different cores gives a noticeable improvement in the late game.

[ZLO_RD]

i don't know about simspeed or how it affects other players but on the side of smoothness and framerate for you: it is so great to set highest priority on FA process
https://www.youtube.com/watch?v=eDlzn9SnUsA
on athlon II x3 440 with unlocked core (meaning 4 core CPU) it boosts FPS from 5-8 to 35-60. pretty insane.

Edit: i thought that usually lack of smoothnes is due to net lag, cause lag can often happen in the beginning of game

[Franck83]

Ty for your answers.

Interesting, If the CPU is bottlenecked, it may impact network speed too.

As Zlo says, using Process hacker and putting FA put in 'Time Critical' mode really add smoothness at same sim speed. I tested it too, and it's true.
That seems to be partially a windows scheduler behaviour problem.

I wonder if we could add measures ingame of CPU and Network responsiveness called periodically.

[JoonasTo]

I’m not 100% on this but I think they are there already.

Don’t remember the names of the console commands though.

[ZLO_RD]

Process hacker is only needed if you want to manually assign cores for individual FA threads. to just set a priority you can use regular task manager.
also i don't think it really impacts sim speed. i even tested it with replay and timer and saw no improvement. but PC was not loaded with other tasks so that is not a big surprise.
Setting that priority just increases you FPS, and may increase sim speed in case of CPU being loaded by many other heavy tasks