Question / Help Seeking further information about Video / Advanced settings

[TheHusky]

To start things off, I wanna say that I have a pretty shitty CPU (Intel Core 2 Quad Q8300 OC @3.00GHz). And since CPU is really important when it comes to streaming, I find myself messing with settings for quite some time to make them work.

Now the most important 2 settings tabs in OBS are probably Video and Advanced. I did play around with them and I made quite a few test streams with each but I'm just not understanding few things about certain settings, for example:

-Under resolution downscale, will a bigger multiplier mean more work for the CPU? Is a downscale from 1920x1080 to 960x540 more work than from 1280x720 to 960x540?

-How much difference is it there between encoding a 540p stream vs 480p stream in terms of CPU usage?

- Under advanced, should I even mess with Process prority or should I leave it on specific value? (I found that when streaming Rainbow 6 The siege, my stream would be a still image unless i put it to Above Normal)

- How much difference is it between veryfast and super fast in terms of CPU usage and stream quality? Currently with my CPU I'm sticking more to the veryfast preset tho I should be probably switching to superfast but I don't want to sacrifice too much of the quality.

I know these are some weird questions, but I'm really interested in some of these. It would really help me get to stream more things with my shitty CPU.


TL;DR: Bunch of questions about Video settings tab and Advanced settings tab

Thanks

 

[sam686]

Downscale mostly depends on graphics card's speed. OBS transfer frames from graphics to CPU after being scaled. CPU usage of OBS depends on the output resolution, and some video encoding settings.

960x540 = 518400 pixels
864x480 = 414720 pixels, this have 80% of 540p. This may help reduce CPU usage a little bit.

It may be ok to set OBS priority to "Above Normal" to avoid stream/record from having problems, or lower game's priority. Windows task manager can adjust CPU priority to many games and programs. Making OBS starve from insufficient CPU from too low of OBS priority and too high of game/program priority causes duplicated/skipped frames.

 

[TheHusky]

Downscale mostly depends on graphics card's speed. OBS transfer frames from graphics to CPU after being scaled. CPU usage of OBS depends on the output resolution, and some video encoding settings.

960x540 = 518400 pixels
864x480 = 414720 pixels, this have 80% of 540p. This may help reduce CPU usage a little bit.

It may be ok to set OBS priority to "Above Normal" to avoid stream/record from having problems, or lower game's priority. Windows task manager can adjust CPU priority to many games and programs. Making OBS starve from insufficient CPU from too low of OBS priority and too high of game/program priority causes duplicated/skipped frames.

Would it be more recommended to set the OBS priority or lower the games priority in the Task Manager?

So basically there's next to no differnce between 540p or 480p? FPS is probably more important in that case (since Estimator keeps telling me to put it to 25 because of my CPU)

 

[sam686]

Priority: Either way works as long as the game's priority is lower then OBS, and/or OBS priority higher then game. The obs setting is better then task manager as you set it "Above normal" once and it will automatically use higher priority even when OBS restarts. Task manager method requires setting priority on every game/program restart.

CPU performance: 25 fps is only %83 of whatever the CPU usage is at 30 fps, less reduction of CPU then reducing from 540p to 480p. intel quad core CPU might be a little more powerful then what the estimator guess if priority changes works fine. Reducing resolution may make small text harder to read. Downscale to exactly half width, half height with bilinear have good results.

If you need to lower CPU, use lower fps for low motion game, or 30 fps with lower resolution for high motion game.