Question / Help 4K60 Pro Elgato + OBS Recording Issues

Fenrir

Fenrir

Forum Admin
Ok, everything looks good there. Can you get one of the sensors tab now as well? Do one with OBS open, but idle, and then get a second shot with OBS actively recording.

Theres got to be some kind of bottleneck here.
 
Fenrir

Fenrir

Forum Admin
Hm. So not a GPU bottleneck.

Close OBS, reopen, and then upload last log. This will contain profiler information from the tests we've been doing and might help pinpoint where the bottleneck is.
 
Fenrir

Fenrir

Forum Admin
Thanks, this is good info, but I'll need a bit to write up next steps at this point, and I need to get to bed here {very late my time, work in the morning and such).

Not giving up, I'll follow up in the morning and we'll figure this out.
 
Leocarian

Leocarian

New Member
Fenrir said:
Thanks, this is good info, but I'll need a bit to write up next steps at this point, and I need to get to bed here {very late my time, work in the morning and such).

Not giving up, I'll follow up in the morning and we'll figure this out.
Click to expand...

Ok, thanks. I am heading to bed as well. Ttyl.
 
R

RytoEX

Forum Admin
Forum Moderator
Developer
I've been chatting with Fenrir outside of this thread, and I've done a little digging on this issue.

There are a few things you can try. First, switch to Advanced Output Mode (you seem to have done this at the end of your last session). Then, try each of these individually and test them out. If none of them alone solves your issue, try combining them. In the Recording tab:
  1. Make sure "Rescale Output" is disabled.
  2. Make sure "Profile" is set to high.
  3. In the NVENC settings, change the Preset to one of the following: Default, High Performance.
  4. In the NVENC settings, disable Two-Pass Encoding.
I suspect #3 with High Performance will solve your problem. Though, your output files may be rather large, so you might have to re-encode them later with something (like Handbrake).


For those interested in some details...

Regarding NVENC performance on the GTX 1080, I couldn't find official performance specs for 4K encoding, and I couldn't find unofficial ones that were relevant to this use case. I was able to find official performance specs for 720p and 1080p encoding, and I could find some 4K encoding tests for Adobe Premiere. Unfortunately, I'll have to extrapolate a bit from what I could find and the data from your logs...

As far as I can tell, NVENC on a GTX 1080 can encode 4K in H.264 at up to about 100 FPS. That is under ideal circumstances with nothing else occurring. The numbers I extrapolated seemed to indicate that a more realistic figure is around 50-70 FPS. I imagine that Shadowplay has less hiccups here because it's doing less work than OBS (OBS does some GPU work prior to encoding, and I think it has to transfer some data between GPU, RAM, and CPU).

I'm not 100% sure of the extrapolated numbers above. I'd love to see some rigorous testing of NVENC performance on Pascal cards at high resolutions (1440p, 2160p/4K).

Hope this helps!
 
Boildown

Boildown

Active Member
Might be worth investingating x264 on UltraFast or even HEVC, as HEVC was designed with high res in mind (on whatever its fastest possible preset is called, I still need to mess with it one of these days). Of course, only if NVEnc is unworkable.

And good call on High Performance NVEnc preset, I bet that does it.
 
R

RytoEX

Forum Admin
Forum Moderator
Developer
@Boildown
From what I've read, HEVC encoding FPS tends to be lower than the encoding FPS for H.264, even on the Pascal cards (sometimes nearly 50% slower) and also between x264 and x265. In this case (for 4K), a High Performance preset would still need to be used, but I'm not sure even that would be able to keep up.
 
R

RytoEX

Forum Admin
Forum Moderator
Developer
For now, I think the OP should confirm that they can get a sustained 60 FPS in any H.264 preset (in OBS, not in Shadowplay) before trying HEVC, which will almost certainly have lower FPS capabilities.
 
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Leocarian

Leocarian

New Member
RytoEX said:
I've been chatting with Fenrir outside of this thread, and I've done a little digging on this issue.

There are a few things you can try. First, switch to Advanced Output Mode (you seem to have done this at the end of your last session). Then, try each of these individually and test them out. If none of them alone solves your issue, try combining them. In the Recording tab:
  1. Make sure "Rescale Output" is disabled.
  2. Make sure "Profile" is set to high.
  3. In the NVENC settings, change the Preset to one of the following: Default, High Performance.
  4. In the NVENC settings, disable Two-Pass Encoding.
I suspect #3 with High Performance will solve your problem. Though, your output files may be rather large, so you might have to re-encode them later with something (like Handbrake).


For those interested in some details...

Regarding NVENC performance on the GTX 1080, I couldn't find official performance specs for 4K encoding, and I couldn't find unofficial ones that were relevant to this use case. I was able to find official performance specs for 720p and 1080p encoding, and I could find some 4K encoding tests for Adobe Premiere. Unfortunately, I'll have to extrapolate a bit from what I could find and the data from your logs...

As far as I can tell, NVENC on a GTX 1080 can encode 4K in H.264 at up to about 100 FPS. That is under ideal circumstances with nothing else occurring. The numbers I extrapolated seemed to indicate that a more realistic figure is around 50-70 FPS. I imagine that Shadowplay has less hiccups here because it's doing less work than OBS (OBS does some GPU work prior to encoding, and I think it has to transfer some data between GPU, RAM, and CPU).

I'm not 100% sure of the extrapolated numbers above. I'd love to see some rigorous testing of NVENC performance on Pascal cards at high resolutions (1440p, 2160p/4K).

Hope this helps!
Click to expand...

Here is log file - https://gist.github.com/573497f1887ad2f8e9a7de9e0e3a811b

Settings were the following

* Nvidia NVENC H.264
* Rescale DISABLED
* CQP 15
* Preset High Performance
* Profile High
* Use Two Encoding Pass DISABLED
* GPU 0
* B-Frames 2

Very good quality sub 20 FPS

P.S. I cannot find NVENC HEVC I only see NVENC H.264 unless that's the same thing?? And other option x264
 
Leocarian

Leocarian

New Member
Just did another test with some more tweaks - so far this has been the best result...almost there..

LOG FILE - https://gist.github.com/d634b781b4a27e66029a702e98ad5750

But quality is starting to drop. I really don't understand this because the 4K Utility from Elgato has no issues at doing flawless capture with no frame drops with 1 click of a button lol. I am afraid to use it because I heard it crashes a lot.
 
Fenrir

Fenrir

Forum Admin
Can you remove the Elgato source and do a test recording to see if you get the same issues? Just record black screen for 30 seconds and upload the current log after.

Something isn't adding up here.
 
Leocarian

Leocarian

New Member
Fenrir said:
Can you remove the Elgato source and do a test recording to see if you get the same issues? Just record black screen for 30 seconds and upload the current log after.

Something isn't adding up here.
Click to expand...

Sure here...

LOG FILE - https://gist.github.com/6bff6cafba0749cb72f409e329964667

This is beyond frustrating... I just recorded almost 2 hours of 4K/60 Footage of Call of Duty: World War II in a single recording and it looks absolutely amazing using 4K Capture Utility. This shit makes 0 sense and in the 4K Utility Capture I am suing Nvidia GTX 1080 as my encoder.

I think at this point I am just gonna record my microphone using Audacity. Only reason I wanted to use OBS is to record both Voice and Game Audio on 1 file but separate tracks for editing and also avoid the crashes on 4K Capture Utility but so far it hasn't actually ever crashed on me so I don't know.
 
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S

sam686

Member
If NVENC doesn't seem to work for you, try intel QuickSync. QuickSync requires supported CPU, enabling integrated graphics in BIOS/Motherboard settings, and intel graphics installed in windows.
 
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