My laptop idles at 8%, when I open OBS it takes up a decent amt, but usually under 50% and my cpu is maxed at 100%. "System" is taking up as much as OBS, and looking at details it's NT Kernal and System referenced. Can't figure out what's causing it or how to fix it. It's not until I launch OBS, and the NT Kernal seems to have been a big problem in the past for others. I've googled it, the kit for the error was last updated for Windows 2000, the cmd prompts suggested for Windows 7-10 either don't execute or run and don't fix it. I have some green screen source files and am running a webcam and game cap but it should be fine, temps are stable, omen has a 1050 and 7th gen i7.
Question / Help OBS causing a system Kernal usage to bring CPU from 8% to 100%my laptop idles at 8%, when I open OBS
- Thread starter Mednar
- Start date
System is CPU time used by the OS and device drivers. Probably one of the devices you are using has bad drivers that are either buggy or inefficient. Update all your drivers. You can use Process Explorer to dig deeper into the system thread to isolate which specific driver is using CPU (look at the "Threads" view of the System process).
Thanks Rich, Do you have specifics on how to narrow it down exactly? I've been trying to work to solve this for 3 days, have updated everything I can think of, and as I said, tried all the troubleshooting I could find via google for Kernel System usage problems, but it was either too outdated to work or yielded no different results.
Show us your OBS log files, it might show something wrong in it.
What resolution is your webcam at? Try to lower USB 2.0 webcam resolution and USB 2.0 capture device down to 720x480 or lower as some USB 2.0 webcams and USB 2.0 capture devices use heavy compression that uses up a lot of CPU, just to capture at 720p 30fps and higher.
USB 2.0 have limited speed. USB 3.0 webcam and USB 3.0 capture devices, or PCI-E, would work much better.
What resolution is your webcam at? Try to lower USB 2.0 webcam resolution and USB 2.0 capture device down to 720x480 or lower as some USB 2.0 webcams and USB 2.0 capture devices use heavy compression that uses up a lot of CPU, just to capture at 720p 30fps and higher.
USB 2.0 have limited speed. USB 3.0 webcam and USB 3.0 capture devices, or PCI-E, would work much better.
You might have too many media sources, which can use up CPU.
You can start a new, empty scene collection, to see which one is causing the problem. The webcam or media sources.
Log shows "Logitech HD Webcam C610", this model is only USB 2.0.
Log shows "Elgato Game Capture HD", but which one are you using? HD60 is compressed USB 2.0.
HD60-S (USB 3.0) and HD60 Pro (PCI-E) have instant game view without compression, other then reduced 4:2:2 or 4:2:0 colorspace.
This limited USB 2.0 speed means the drivers is doing the decompression of MJPG, H264, or something, compressed by hardware webcam to fit limited USB 2.0 speed, and using lots of CPU to decompress. USB 3.0 will help avoid the need for CPU heavy compression.
Make sure your CPU isn't throttled / slowed down from overheating (HWMonitor or something), or from Dell's "AC Adapter cannot be determined".
You can start a new, empty scene collection, to see which one is causing the problem. The webcam or media sources.
Log shows "Logitech HD Webcam C610", this model is only USB 2.0.
Log shows "Elgato Game Capture HD", but which one are you using? HD60 is compressed USB 2.0.
HD60-S (USB 3.0) and HD60 Pro (PCI-E) have instant game view without compression, other then reduced 4:2:2 or 4:2:0 colorspace.
This limited USB 2.0 speed means the drivers is doing the decompression of MJPG, H264, or something, compressed by hardware webcam to fit limited USB 2.0 speed, and using lots of CPU to decompress. USB 3.0 will help avoid the need for CPU heavy compression.
Make sure your CPU isn't throttled / slowed down from overheating (HWMonitor or something), or from Dell's "AC Adapter cannot be determined".
If that were the case I would expect it to show as OBS usage and not "System" though wouldn't you? I have no problem streaming on my desktop with the setup, which is also an i7 CPU. Granted laptop ones are significantly weaker, the desktop one rarely tops 15% for OBS. HD60 is the Elgato card I'm using to transmit video from the desktop to the laptop, and doesn't use USB 3 at all. The webcam is also USB 2. I've adjusted all of the power settings possible for the Nvidia card and within windows to make sure the HP settings aren't slowing it down. This is why I'm so confused. I've spent over 20 hours this week trying to fix it. Where I'm stuck is the "system" using so much and not being able to tell why. Under details it referenced the Kernel which had outdated fixes that can no longer run/apply or ones that didn't work.
Did you check CPU usage with both elgato capture card and webcam unplugged or turned off?
What is the CPU usage on a blank, empty scene collection?
USB 2.0 is heavily compressed for anything over about 720x480 30 fps, due to limited speed, about 40 MB/s (the fastest USB 2.0 flash drive).
1920x1080 at 60 fps with 1.5 bytes per pixel (for i420 / YV12) is 93 MB/s, over the limit of USB 2.0.
As OBS,Studio see your webcam as an input of i420 (4:2:0), and elgato as only UYVY (4:2:2), not h264 or mjpg, and is over a slow USB 2.0, somewhere between OBS and capture device is being compressed and decompressed, most likely the Elgato and/or webcam drivers. Cannot really hide the CPU usage of decompression of slow USB 2.0.
Edit: If you want to know which HDMI capture I went for, here it is.
I have this HDMI capture that support USB 2.0 (MJPG) and USB 3.0 (YUY2 or MJPG), 720p60 or 1080p60. MJPG is selectable in OBS-Studio and actually logs if it uses MJPG.
https://www.amazon.com/Video-Capture-Device-1080P-Grabber/dp/B01N4SM7H6/ref=sr_1_3
Being able to select MJPG is good, knowing that OBS-Studio would be doing the MJPG decoding and not the system drivers. YUY2 have less CPU usage then MJPG.
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so when I lowered my stuff to 720p 60fps I now am between 60 and 80% cpu usage. So I'm stuck with 720 despite having a 7th gen i7 and a 1050 card? That feels REALLY bad... With an empty obs scene and nothing plugged into usb it's obviously very small cpu usage. I'm using my usb3 port but I'm guessing that compression bottleneck is build into the elgato hardware? As for your capture device, I appreciate you letting me know, but being I use it for xbox too, I need the output so the feed goes to a monitor to play on as well. Based on what I saw yours wouldn't work that way.
It does work with HDMI splitter, which I also use. One goes to capture device, the other goes to HDMI monitor -- or with HDMI to VGA converter on old CRT monitor for less latency. HDMI splitter also works without needing computer to be powered on. Originally used HDMI splitter for outdated AverMedia C027 (PCI-E, no 1080p support, no pass-through).
edit: If you want to go with Elgato you can try HD60-S USB 3.0 and it has pass-through and instant game view with minimal delay in OBS-Studio and less CPU usage then USB 2.0, but it is USB 3.0 only, won't support slower USB 2.0.
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I got the capture card referenced above and while it now seems to help with the cpu issue (assuming that remains true after fixing my new issue), I can't seem to get audio to come through. Telling the usb capture device to listen to my mic does not work, no mic goes into obs on the streaming PC. I tried running a voice meter application outputting to the usb capture device but no desktop audio is coming through to the streaming pc either. I can always hook up my mic to the streaming pc, although I would like to be able to use it on my gaming rig. The desktop audio is 100% needed regardless.
In OBS-Studio video capture device, try "Use Custom Audio Device" "Microphone (USB Audio Device)"
I got the audio working - part of the time. Having a larger issue with this cap card that when loading the software it often loads only 1/4 of the screen, and the audio doesn't come through at that point any more either. IDK how to get this card to work consistently where it displays the entire screen and consistently puts through volume.
in OBS-Studio, Right click video capture device, transform, fit to screen.
Screenshot of it showing only 1/4 of the screen?
Show us more recent OBS-Studio logs?
Did you try Video capture settings, stop device then start device?
Try different USB ports? Try to use USB 3.0 port for USB 3.0 capture device.
If you use both USB webcam and USB capture device, both plugged into a slower USB 2.0, they might be taking away each other's USB bandwidth. Each USB 2.0 controller only have a shared 40 MB/s bandwidth. Can see this with windows device manager, view, devices by connection.
Edit: if capturing the gaming computer, and gaming computer's screen moves with the mouse pointer, it is a gaming computer problem with cloning displays and too high of resolution.
As for audio, you could try a VB-Audio network software (no hardware), although I haven't tried it myself yet. https://www.google.com/search?q=vb-audio+network Uncompressed stereo audio is only about 1.5 Mbps.
Screenshot of it showing only 1/4 of the screen?
Show us more recent OBS-Studio logs?
Did you try Video capture settings, stop device then start device?
Try different USB ports? Try to use USB 3.0 port for USB 3.0 capture device.
If you use both USB webcam and USB capture device, both plugged into a slower USB 2.0, they might be taking away each other's USB bandwidth. Each USB 2.0 controller only have a shared 40 MB/s bandwidth. Can see this with windows device manager, view, devices by connection.
Edit: if capturing the gaming computer, and gaming computer's screen moves with the mouse pointer, it is a gaming computer problem with cloning displays and too high of resolution.
As for audio, you could try a VB-Audio network software (no hardware), although I haven't tried it myself yet. https://www.google.com/search?q=vb-audio+network Uncompressed stereo audio is only about 1.5 Mbps.
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Yes I've tried deactivating and reactivating many times as well as the transform settings, but all that does is make the 1/4 screen larger within the obs scene, doesn't expand the FoV. I'm using a dedicated USB 3.0 port for the cap card on it's own. Webcam is in a hub in a different usb3 port. Again, the problem seems to be exclusively with the capture card/display device, as computer load no longer appears to be an issue.
Attached are all recent logs from the last 24 hours along with the screen shot of the 1/4 screen both within the overlay and also as fit to screen. As a side note, you can see on the left of the fit to screen screen shot here, and the couple times it randomly displayed the full screen to me, there were black borders around the video image. Not a huge idea as I can just expand it larger than the window under the overlay layer, but I still found it curious why it was displaying that way. As discussed I'm running a splitter, one to a monitor and the other to this capture device, and the device displays these black bars but the monitor does not.
