When I use x264, I get frames dropped due to rendering lag- why is this happening? 3900x, 2070 Super, 32 GB ram - LOG inside

[ok7]

Hi all. I am new to all of this and am currently experimenting with x264 vs NVENC to see what gives me better performance (testing both 1080p60 and 720p60).

For some reason, when I run x264, I get 13-15% "frames missed due to rendering lag", for both 720p60 and 1080p60. When I use NVENC, that number falls to 0.0-0.1%.

I am confused as to why I would be dropping frames due to rendering (a GPU operation) when I encode with my CPU. If anything, I would expect the opposite. I'm using a 3900x, 2070 Super, 32GB ram

Here is my log file. including the 4 relevant tests here (NVENC/x264 + 1080/720p).

Log: https://obsproject.com/logs/O82q8mp-cQQfLDV2

• 21:28 = x264 1080p60 (4.2% rendering lag)
• 21:39 = x264 720p60 (13.0% rendering lag, which is surprising given 1080p only had 4.2%)
• 21:48 = NVENC 720p60 - no rendering lag
• 21:56 = NVENC 1080p60 - no rendering lag

And here is the OBS analysis: https://obsproject.com/tools/analyzer?log_url=https://obsproject.com/logs/O82q8mp-cQQfLDV2

Any idea what could be causing this? I am running OBS in administrator mode.

Thanks everyone.

 

[Deleted member 121471]

Turing encoder is equivalent to x264 fast-medium with nearly 0 performance impact, if set correctly.

Rendering lag merely means your GPU is being overload, which is why capping framerates is a common recommendation.

Can you explain why you chose to capture 2 different monitors in the same scene?

Lastly, your internet connection seems highly unstable, is it possible to connect through ethernet or, at least, powerline?

 

[ok7]

Thanks for the quick reply! I've responded below.

Turing encoder is equivalent to x264 fast-medium with nearly 0 performance impact, if set correctly.

Yep, which makes the large difference even more confusing...

Can you explain why you chose to capture 2 different monitors in the same scene?

Ah that was me being a noob and quickly creating some scenes (I'm assuming you are talking about the "watching videos" scene?). In these tests, I was only using the "Gameplay" scene, which only has 1 monitor source.

Lastly, your internet connection seems highly unstable, is it possible to connect through ethernet or, at least, powerline?

At this exact moment, I can't get an ethernet here, but once I move, I will have an ethernet connect. That said, I don't think it would affect frames lost to rendering, would it? (esp given it is all fine on NVENC)

 

[Deleted member 121471]

Just to get it out of the way first, internet stability won't affect anything in terms of rendering and encoding.

First, turn on Windows 10 "Game Mode" and Windows Defender, turn off Malwarebytes.

I recommend creating a fresh scene collection (OSB Window top menu) and adding only a single capture source, either game, window or display capture source, in order of best to worst performance, whichever works first. Preferably, your main capture source, which seems to be a chess board or something.

You can then test either CPU encoding at "Medium" preset or NVENC at "Quality" Preset then disable both "Lookahead" and "Psycho Visual Tuning".

If there are no issues, add another item to your scene until something changes and then you'll know what was causing what you're experiencing.

 

[Lawrence_SoCal]

For some reason, when I run x264, I get 13-15% "frames missed due to rendering lag", for both 720p60 and 1080p60. When I use NVENC, that number falls to 0.0-0.1%.
I am confused as to why I would be dropping frames due to rendering (a GPU operation) when I encode with my CPU. If anything, I would expect the opposite.

NVENC is offloading the rendering to the GPU
x264 on the other hand, is using the CPU to render (and is therefore competing with whatever else you are using the CPU for). I'd expect CPU monitoring to show a very high sustained rate (if not 100% utilization, right?) hence the lag

running in admin is typically needed for GPU scheduling, and is typically needed when under-resourced/over-tasked. If using NVENC meets your needs, and you have plenty of hardware, you may not need to run as Admin, which would be a security improvement