Nvenc HEVC performance in 2021

[Galach]

I'm using Nvenc h264 for recording and recently tried to set HEVC via FFmpeg. Tried to match settings with h264 and as a result got laggy recording which my PC couldn't handle.
On paper HEVC is twice more bitrate efficient than h264 but for now I made a conclusion that much easier to set h264 with 2x, 3x and more bitrate and render it in HEVC in post than record purely in HEVC.
It's a bit strange for me because I thought that more compressed codec must be easier to handle for hardware (most mirrorless cameras now using HEVC to get better settings than in they can in h264 like 10bit 4:2:2; shadow play uses hevc for 8k recording - but I just tried to match h264 settings to get more quality for same bitrate and failed).

Maybe I made a mistake in setup (it's quite complicated in ffmpeg). But I also tried another program which supports HEVC by default and get same bad performance with same settings.
So I decided to ask forum. Can HEVC now give more efficiency in quality and performance or it's not really optimized for now and that's why OBS doesn't include it in non-ffmpeg recording setup.

 

[Galach]

P.S. I tried to match this settings. On Laptop with RTX 3060 (105tdp). 4k60 recording

 

[Deleted member 121471]

HEVC recordings require less bitrate to maintain the same quality as h. 264 but the computational cost of both encoding and decoding is significantly higher.

 

[Galach]

HEVC recordings require less bitrate to maintain the same quality as h. 264 but the computational cost of both encoding and decoding is significantly higher.

So is there any sense of using it now when you can to record h264 with higher bitrate for less performance cost? Sense in quality aspect, not file sizes

 

[Deleted member 121471]

It makes no sense to use fixed bitrate for personal recordings, as that limitation only applies to streaming online, due to infrastructure limitations.

Recording with h.264 encoder and "CRF" or "CQP" rate control, set to a value between 16-20 (lower value = higher quality at the cost of larger storage requirement) is what I'd recommend. It's the most reliable way to have a consistent image quality, using no more and no less bitrate than needed.

You can then reencode the resulting file using whichever quality settings you want the end file to be. I'd recommend H.265 for long term storage only.

 

[Galach]

I made some pixel peeping tests of YT after uploading and made a conclusion that such a huge bitrate which CQP 16 gives to 4K60 recording (about 500k and more) is visually identical to CBR 300k (on YouTube player, raw files of CQP are much better in high action). That's why I started to use CBR to get less file sizes. Maybe I should try to increase CQP values to find optimal bitrate but for now I didn't make tests in this direction