Question / Help Encoding overload ~20% dropped frames with AMD VCE despite no FPS drop ingame

[SaulSlendamann]

I'm having a very specific problem with OBS Studio.

I am using the AMD VCE encoder when I stream, but I'm experiencing very specific areas in games that will cause the encoder to overload despite
-No bitrate fluctuation
-No ingame FPS fluctuation
This is very strange to me. I would expect that my FPS would drop if the encoder is overloading my GPU, so I don't know what's going on here.

The framedrops happen at very specific times and ONLY when using the AMD VCE encoder.

Most notably are during rain in ETS2, and when any smoke effect appears in Dark Souls 2 (which I have an example of here https://youtu.be/j4Onb-7u6g0?t=3673 - as you can tell, the game runs perfectly until smoke appears and then it stutters like crazy. Walking across the chain rope also shows massive stuttering due to all the snow effects. After crossing the chain, the stuttering stops almost immediately. Skip throughout the video and you will see that the dropped frames also occur when I enter fog-gates or sit down at a bonfire).

I do not experience "Encoding overload" warnings in games where I experience FPS drops, so I don't think the problem has anything to do with the actual game performance. I (seemingly) only experience the warning in games where there is seemingly perfect performance. I have tried a number of things to fix this, but I'm out of guesses. Lowering bitrate, resolution or FPS makes no difference, and the dropped frames only occur at very specific times.

I have a qualified guess that this is an issue that likely has to do with an option that can't yet be changed with AMD VCE encoding in OBS Studio, but OBS Classic with the AMD VCE injector doesn't work on my system so I have no way of trying that out for myself.

I can, of course, still stream games using my CPU. But that means a severe FPS hit, so I'd much rather use my GPU. Has anyone else stumbled upon this issue and know of a fix? If not, well, consider this a bug report ;)

Thank you in advance!

Note: the uploaded log file is from me just opening up Dark Souls 2 and walking around in that area where the frame drops occur. I don't have a log file from any of the streams, I'm afraid.

LOG: http://pastebin.com/E3tT8frn

 

[max20091]

It's encoding lag, you should lock your in-game FPS to 60 or what number you like to reduce GPU using.

analyzed result
Encoder: Number of skipped frames due to encoding lag: 6174 (70.0%)
In-game: Number of lagged frames due to rendering lag/stalls: 124 (1.4%)

 

[SaulSlendamann]

It's encoding lag, you should lock your in-game FPS to 60 or what number you like to reduce GPU using.

analyzed result
Encoder: Number of skipped frames due to encoding lag: 6174 (70.0%)
In-game: Number of lagged frames due to rendering lag/stalls: 124 (1.4%)

Hello Max20091

Thanks for the help. This is a very late response, but it is simply because I haven't had time to stream.

I took your advice and tried limiting my frames to 60 FPS - and it seems to have fixed nearly all the stuttering issues. Skipped frames is down to below 0.5% now. I will continue to experiment further and see if I can eradicate this problem completely.

 

[BluesAdam]

It is because when fps is unlimited, your gpu probably hits 100% usage. If at any moment your GPU hits 100% usage and/or full VRAM usage, your recording will stutter. People tend to believe that GPU encoding is a resource free way to record videos, but it's not. You need extra processing power and vram to record videos.