Question / Help OBS 23: better to use OLD NVENC on 2 PC setup via NDI?
- Thread starter Jaybonaut
- Start date
Jaybonaut
Member
Why, if I may ask, do you recommend something that has no benefit?
Hey mate, I think he just looks like it's jumbled cause of your title vs body text. Your question in the title was about old NVENC and he was directly answering that, instead of answering the body text which asks about the new version.
The new NVENC implementation is definitely better on the streaming PC. Here's how it compares to x264:
https://unrealaussies.com/tech/nvenc-x264-obs/
Sadly that graph doesn't include the "old" implementation. However, you can test it yourself. Just do a lossless recording for about 30 seconds, then grab FFMPEG. Do this command to simulate the old implementation:
ffmpeg -i Original.mkv -c:v h264_nvenc -preset:v hq -profile high -level 4.2 -b:v 5000k -an -f matroska Turing_MaxQ_5000.mkv
Then do this command to simulate the new implementation:
ffmpeg -i Original.mkv -c:v h264_nvenc -preset:v slow -profile high -level 4.2 -b:v 5000k -rc-lookahead:v 32 -g 120 -an -f matroska Turing_HQ_5000.mkv
The difference is 2-pass encoding and lookahead. Then, use whatever method you prefer to judge the difference. You can try looking at the end result yourself, but the difference may be very subtle, if you wanna go this route, use a bitrate that is somewhat challenging for your video resolution. I prefer VMAF to test the difference, but you can use FMSE or SSIM if you prefer.
It sounds like a pain, but if you MUST know FOR SURE then the only way is to test it yourself. If you're willing to trust the answers you get here, the answer is the new one.
The new NVENC implementation is definitely better on the streaming PC. Here's how it compares to x264:
https://unrealaussies.com/tech/nvenc-x264-obs/
Sadly that graph doesn't include the "old" implementation. However, you can test it yourself. Just do a lossless recording for about 30 seconds, then grab FFMPEG. Do this command to simulate the old implementation:
ffmpeg -i Original.mkv -c:v h264_nvenc -preset:v hq -profile high -level 4.2 -b:v 5000k -an -f matroska Turing_MaxQ_5000.mkv
Then do this command to simulate the new implementation:
ffmpeg -i Original.mkv -c:v h264_nvenc -preset:v slow -profile high -level 4.2 -b:v 5000k -rc-lookahead:v 32 -g 120 -an -f matroska Turing_HQ_5000.mkv
The difference is 2-pass encoding and lookahead. Then, use whatever method you prefer to judge the difference. You can try looking at the end result yourself, but the difference may be very subtle, if you wanna go this route, use a bitrate that is somewhat challenging for your video resolution. I prefer VMAF to test the difference, but you can use FMSE or SSIM if you prefer.
It sounds like a pain, but if you MUST know FOR SURE then the only way is to test it yourself. If you're willing to trust the answers you get here, the answer is the new one.
Last edited:
My apologies for the confusion. There are no benefit to using the old NVENC. New NVENC has better performance because it keeps everything on your GPU. New NVENC also has extra options that can result in better visual quality.
Jaybonaut
Member
...and these options do not go into effect when using a 2 PC setup using NDI? I still use NVENC to transcode on the 2nd PC you realize. By the way, if it wasn't clear earlier, I do appreciate your help in understanding.
Jaybonaut
Member
Typically I don't do 2 pass. I should test that though - see my 2nd PC doubles as a Plex server that various family members use outside of my home. I do have hardware transcoding turned on in Plex but it is smart enough to know when to use the CPU. Unfortunately we still have to deal with Nvidia's forced 2 transcode limit without going toward a Quadro card.
2-Pass in OBS is fine because it uses CUDA for the first pass and NVENC for the second. It wont occupy 2 separate encodes. Let me put it this way, to the best of my knowledge, the new OBS NVENC option can do everything the old one does, and more. There is literally nothing you can do on the old one that you can't do on the new one if your computer can use it.