Webcam-only - inconsistent huge CPU spikes/plateaus

[A-Wax]

Please help - I'm at my wits' end!

I've been running OBS for a couple of years pretty much without complaint, using two Logitech C922s and a Behringer UCA202 into my Asus laptop. Over the last few weeks I've been having issues where using a webcam starts ok but then ends up with CPU usage rocketing to 50/60/higher percent, with no other programs running - it absolutely destroys my streaming. It also seems to be inconsistent, which is absolutely maddening. If I switch the source to one that has no webcam, the CPU usage falls to single digits.

• Webcams run full-screen, but only one at once, and both at 720p
• Output resolution is 720p, and I'm aiming for 30fps at 3000kbps.
• Webcam audio is not used, only the USB audio from the Behringer - 48kHz, as is the OBS output
• No Windows updates are pending
• Again - this did previously run happily

Logs are uploaded here, via OBS. If anyone can help, I'd be hugely grateful!

 

[A-Wax]

I should clarify - I'm not actively including the audio from either webcam as sources in any of my scenes, but I don't know if it's somehow being pulled into OBS regardless and then consuming processing time?

Here's a shorter log from the same day, from a test stream that showed the same issues, but which also generated fewer warnings from log analysis.

 

[SLYFX_Gaming]

Sad to say this problem is still a thing, my dude!

It happens most of the time when Im running my camera thru a secondary software like xsplit vcam or manycam. (even having logitech ghub open causes the issue). Id like to add this for a long while this issue was never a thing (3900x cpu, 3060ti gpu, 64 ram, 6000 bitrate with no recording going on at all on a 2 PC setup .... Playing on gaming PC and using NDI to send it to stream pc ... and im not sending 4k resolution. im sending it at the same output resolution that the stream pc is gonna stream at 1920x1080).

it started like a year ago and after stressing it and having no answers for my viewers i was FINALLY able to narrow down and identify the cause(s). I even had to completely rebuild my obs scene collection from scratch to figure it out. When it was still happening even with only a game feed, a camera feed, and the audio (no sources otherwise) I just said screw it and been streaming using just the base logitech brio camera (no virtual green screen from xsplit, and no color or image enhancements from ghub) and havent had any issues since. (BUT IT SUCKS WHEN I HAD NO ISSUE WITH XSPLIT FOR 2 YEARS ON THE SAME DEVICE)

My normal cpu% at the bottom of my OBS when im live will typically show anywhere from 3-8% cpu (and 8% is even when i start to notice its getting higher than normal). Ive seen the spike happen on games as small as among us and peak and schedule 1. But ive also seen no issues streaming games as big as cyberpunk, black myth wukong, dune awakening, new world (again i have a 2 PC setup to minimize cpu and gpu on my stream pc (3900x/3060ti).

Needs a fix for sure!