Stutter While Recording

So this is a specific issue I haven't seen anybody else have directly. First of all, the PC specs:

Zotac Gaming RTX 2080ti 1.35GHz

Intel i9-9900k 4.7GHz on Aorus Z390 ATX board

4x 8MB DDR4 3000MHz

Win 10 64-bit

Monitor Samsung C49RG9 49.0" 5120x1440 120 Hz Monitor on one DP 1.4 cable to GPU

Storage: 1TB Samsung 970 EVO NVMe

4TB Samsung 860 QVO

Recording with OBS

When I am recording DCS through OBS, the game itself runs at about 40-80fps on pretty high settings. OBS, however, experiences a lot of stuttering as it encodes and it shows in the recording. Whenever I switch to OBS and make it the foreground application, it then records the game at 60fps with no issue. The game itself also maintains its same 40-80fps. Of course while flying, I cannot keep OBS as the prime window since the HOTAS no longer applies input to the game.

EDIT: Also to note, this issue only began when I swapped out my monitor from 2x 60Hz 24" monitors to the single 120Hz 49" monitor.

I figure somewhere either in OBS, Windows, or DCS there is an option to limit how much GPU power is being dedicated to DCS.

Any help would be greatly appreciated here.

Recording settings attached. https://gyazo.com/1b45c435ff8fee2016223b3a8fec2a14

https://gyazo.com/70008512fb3b5a6d21287a17616d094e

What encoder are you using in OBS? hazarding a guess if you're using NVENC, your GPU is getting completely saturated and so the OBS encoding is getting depriortised when the window doesn't have focus.

Regarding happening after you upgraded monitor, the higher resolution will put more demand on GPU, and if you used to fly with vsync then with 120hz there'll be even more asked of it.

Given your system I'd recommend using the x264 (CPU) encoder, rather than GPU. Because DCS doesn't scale on threads/cores, you've got masses of CPU time not contributing, whereas I'm guessing the GPU is maxed out.

Yes. In the recording settings, I have NVENC enabled. Is swapping to x264 going to be the only option here? I figured that a 2080ti would be beefy enough to handle 1440x60 recording. Again, the OBS seems to work that way if it is the focused window without impact to the game itself.

I use action video recorder with the option use multicore on.

Still on a 4 core pc and 1080ti, no problems recording 1440p @ 60.

The only time you can use the GPU is when re-rendering for YouTube I was thinking, not in sim.

Yes. In the recording settings, I have NVENC enabled. Is swapping to x264 going to be the only option here? I figured that a 2080ti would be beefy enough to handle 1440x60 recording. Again, the OBS seems to work that way if it is the focused window without impact to the game itself.

Open task manager while playing and look at your GPU load, if GPU is hitting 100% that will confirm the problem. Windows allocates system resources based on the selected app, so when game is selected it's being prioritised, and vice versa.

You could add a frame rate cap to DCS or lower settings to free up GPU time for OBS, but considering you have vast amounts on CPU resources not doing anything I wouldn't recommend that.

x264 with CPU profile of fast/medium (or below) will give superior results anyway, so you have nothing to lose.

x264 with CPU profile of fast/medium (or below) will give superior results anyway, so you have nothing to lose.

Open task manager while playing and look at your GPU load, if GPU is hitting 100% that will confirm the problem. Windows allocates system resources based on the selected app, so when game is selected it's being prioritised, and vice versa.

You could add a frame rate cap to DCS or lower settings to free up GPU time for OBS

As you have an nvidia card you're best off setting the frame rate limit in the nvidia control panel - attached a pic of where to find it.

I've also attached a picture of my OBS recording settings, I have a very similar system to you (i9-9900k + 2080 non-ti).

I've never seen the CRF option before as most usually recommend Lossless or CBR. Capping the FPS at 70 along with CRF set how you have it seems to have done the trick. Thank you!

I wanted to post this 2 days ago but forgot, I may be a bit late but it can still matter:

Use a process utility to set the CPU Affinity of the recording process to use only like two cores, or a number that leaves DCS with at least 2 or 3 cores, however you can leave DCS affinity default.

If you have SMT/HT enabled you have to figure out which logical processor or processors correspont to a physical core and you have to double the number, so you would get rid of 4 or 6 logical processors off the recording process affinity list.

Live x264 compression can spawn up to 8 threads or more depending on the CPU and a multitude of factors that the developers of the recording software set which will fight over CPU time and "steal" resources from DCS.

To limit the FPS of DCS, you need to create a text file autoexec.cfg in your DCS profile in Saved Games\DCS\Config folder, with a line: options.graphics.maxfps = 75

I don't know of a 70 hz monitor but I have a 75Hz one currently.

Use a process utility to set the CPU Affinity of the recording process to use only like two cores, or a number that leaves DCS with at least 2 or 3 cores, however you can leave DCS affinity default.

Live x264 compression can spawn up to 8 threads or more depending on the CPU and a multitude of factors that the developers of the recording software set which will fight over CPU time and "steal" resources from DCS. If you have SMT/HT enabled you have to figure out which logical processor or processors correspont to a physical core and you have to double the number, so you would get rid of 4 or 6 logical processors off the recording process affinity list.

As for the monitor, it's mentioned up above. It's 120Hz.

Bitrate

reducing bitrate from 60,000 to 45,000

This may be your issue. For bitrate whilst recording try 6000 - 10000 max.

This may be your issue. For bitrate whilst recording try 6000 - 10000 max.

I assume you're talking about something like Process Lasso.

This is something a normal task manager can do.

Well as I mentioned, it's an Intel i9-9900k so 8C/16T. Unsure of which of those are logical cores.

 

As for the monitor, it's mentioned up above. It's 120Hz.

AFAIK, usually it's alternating, 0 & 1, 2 & 3, 4 & 5, so you would go and disable all even or all odd numbers, but the task manager and the infrastructure should be built to support showing the freaking detailed topology of each CPU in a fully visualized manner, but no, a billion dollar company just can't have that kind of vision, they're busy on updating the icons for their new social features and other nonsense, bleh.

You'll have to check that with Process Hacker or similar, how many transcoding threads does OBS use on your system, but I didn't play with OBS for that long or deeply to know if there's some advanced thread options in it, I didn't saw them myself, so it's most likely using up to 8 or more, I think that transcoding doesn't parallel to infinity so they may not be using more than 8 or more than 12 in any case but that's just my opinion right now.