My screen source shuttering every 12 minutes

[SteevE-G]

CPU : i9 10900 (10C/20T)
GPU : Nvidia 3090
(so it's on a PCIe gen3)

Hello everyone and thank you for participating and helping people!

My issue is not related to the encoding, recording or streaming by itself. That's why I don't include log files.
It is my source (desktop) who is slowing down every 12 minutes, and for a duration of 20 to 30 seconds (I mean instead of being consistent 60fps like all the rest of the time, during this short timeframe it slows down to 30fps, and it comes back to 60 fps).
PS: I said 60fps as an exemple, but I have exactly the same issue if I setup OBS in 30fps, 60fps, or even 120fps.

The strange thing is it doesn't depend of the resolution, I can setup Windows in 5K, 4K, HD, it works perfectly except this lag every 12 minutes.

So of course it's not depending of encoder too, even just looking at the preview in OBS it happens. So of course it'll happens also if I record or stream, with no relation to the settings or the encoder I choose.

My feeling is there is something in the background who is launched every 12 minutes by Windows. But unfortunately, after checking the task scheduler, trying to look at the task manager to see if any task is poping every 12 minutes, I also removed all startup apps, and even tried starting windows in minimal mode...
I was even deeper and try to overclock the bus clock of the motherboard and also try an OC of the CPU and GPU, just for testing.
I also tried to switch off the hyper-threading.

I forgot the most important : There is NO lag on screen in real, if I'm playing a game, or using an app, or just let playing with the mouse on an idle Windows, I never have any lag in real, it's just the picture coming into OBS which is affected.

So when I record or stream something, because the issue is on the source itself, OBS says there were no drop or lost frame, and the log is clean of course, because x264 or NVEnc are all good, for sure the problem is not in the encoding because it happens even without encoding (just in preview).

Please, is there someone who have any idea of what I have to check in Windows or OBS settings?

For info, I already try basic things like game mode on/off in windows settings, put maximum performances on energy settings of Windows, trying without internet connexion, disconnecting all secondary drives and keeping only the NVMe used by system and OBS...

At this point, any idea will be welcome.

THANK YOU in advance and Happy New Year guys!

 

[BluePeer]

" I forgot the most important : There is NO lag on screen in real, "
if you habe a Gsync/freesync display
the Display refresh is dynamic related to the "FPS" the gpu send to it
Human Eyes only "register" changes, so a 30FPS drops looks stutter on a Old not gsync 60HZ display and smooth on a 200hz gsync

The reason for the "drop" related on the Specific time frame and duration you found,make me to think its a "software" that create this "issue"
that can have "Multiple" reasons

One can be if you have 2+ displays with differenz refresh rates 1. 144 2. 120 3. 60hz
if a application on display 3 gets Active (hardwareacceleration) Windows old known bug try to find a comon FPS for all and with math problem to match 144:3 is like 48 (there need to be below the smallest refresh rate)
this is for me the most comon reason for drop below 60 you told

Another is that there is a 3D Application running that use "Vsync" like a 3D Background animation software that forced from windows in gaming to low cpu usage and result in a low fps and force the gpu on the "vsync" to reduce the refresh rate to the application frame rate
i call it "Vsync" but is it not realy a "Vsync" its more a bug related to Gsync/freesync that force the refresh rate to the application rate if the software creator not follow the instructions of that features that result in a "limit" of the gpu framebuffer

for me it sounds like you verified that CPU/GPU Load/Thermals/Powersettings are not the issue
then it is a big chance that you have a issue in this range

But without clear details (mostly include) a logfile we can not tell if this is a OBS related issue
but it is 95% not OBS related Issue

 

[SteevE-G]

Thanks @BluePeer for your answer !
I'm using only 1 screen and it's set up in 60Hz. So my Windows, my game, and my recording are all in 60Hz so I think it's pretty clean about that. The game is running perfectly smooth on screen and also in the recording except every 12 minutes when it's stuttering.

BUT thanks to you I'm actually very close to find a solution. Because thanks to you I made more tests with vertical sync, G-Sync, all of this, and I got a clearly better result, i don't know why, by activating G-Sync (while my monitor is not supposed to be G-Sync compatible... which is funny at the end).

Thanks to the activation of G-Sync in the Nvidia panel, my game is now G-Sync activated, and the OBS stuttering every 12 minutes is gone.

But it's not 100% perfect because now I have a mini stuttering every 25 seconds. So it's clearly more acceptable than the previous issue but it's still not perfect. I have to solve that now but maybe if I test deeper with different settings about g-sync and vertical sync, I will probably find the solution. At least it looks like it's about sync. It's a great process in my research ☺

Of course it's still not an issue of OBS. For him, there is just 0 drop frame both in rendering and encoding, even on a 1-hour recording test I did. Log is perfectly clean. So I just have to understand and manage how Nvidia Sync is working and hopefully it'll be ok.

Thank you very much for your help, because without you I would probably never tried to changed sync settings since I don't have a G-Sync monitor...