HandBrake AV1 (SVT) and Ryzen 9 7950x

[ctsdh0]

Hi. I believe i was registered here many years ago, but had to create new account, so hi!

I have question about asiftware AV1 encoding performance while using Ryzen 7950x.
I "webripped" Pulp Fiction 3440x1440 using my rtx4070 in AV1 high quality, so recorded file had 12GB. My aim was to compare speed of rtx av1 encoding vs CPU speed ( file sizes, quality with this same bitrate ).

So my rtx4070 re-encode source file to ( again ) AV1 highest possible quality in 55mins ( it was approx 130-150fps )
With ryzen 7950x i used same settings, but 2-pass and standard quality "5" for AV1 (SVT ) encoder built in HandBrake and finally it took 5H:50mins, however - 1st pass was 180-200fps 100% CPU in use , where 2nd pass was jumping between 18-47-50 FPS with final average FPS 31, but i noticed CPU usage while 2-pass encoding in progress was between 25 to 50% ( all 16 cores/32threads in use ), jumping to 80-90% for very short time couple of times, i would say on average it was close to 50%... Is this something normal and it's just unoptimized encoder or some other reason/bottleneck etc ? It was using all cores/threads, however usage % for most of the time over 5h50mins stayed at 50%

Any ideas what could be cousing this ?

Thanks,
cts

[jagabo]

Two pass encoders typically use fast, highly simplified settings for the first pass -- because all they are doing is generating information about how complex each shot is. The second pass is where the real work is done, so it takes much longer.