x264 1st pass won't using max CPU

[IbrahimKh]

I'm using xtaxrip x64 to encode video

the problem is, x264.exe often only use 30% of CPU power on most of my video


But sometimes, I got 99% CPU usage on some video, which this I want on all videos
x264 [info]: Weighted P-Frames: Y:3.3% UV:1.7%
x264 [info]: kb/s:1091.13
encoded 247371 frames, 105.17 fps, 1091.13 kb/s

Start: 6:26:10 AM
End: 7:05:23 AM
Duration: 00:39:13

I'm using same preset, so can ayone tell me what's wrong?

---
Preset (99% CPU power on 1st pass)
x264.exe --preset slower --tune film --pass 1 --bitrate 1099 --level 4 --vbv-bufsize 17500 --vbv-maxrate 20000 --merange 24 --aq-mode 3 --aq-strength 0.8 --stats

Preset (only 30% CPU power) on most my videos
x264.exe --preset slower --tune film --pass 1 --bitrate 1089 --level 4 --ref 5 --vbv-bufsize 17500 --vbv-maxrate 20000 --merange 24 --aq-mode 3 --aq-strength 0.8


I tried played with many x264 version but still no luck
--
my CPU
https://puu.sh/qM1qF.png

[AMED]

Try swtiching from AVISynth to Vapoursynth. I saw a 2 x speed increase on a Dual socket E5645 server.

You might need to update Staxrip to the development version.

[Groucho2004]

There is nothing wrong. x264 generally doesn't max out the CPU on the first pass because "--pass 1" uses a different set of parameters than "--pass 2" in order to speed up the first pass. This goes along with lower CPU usage on multi core CPUs.

For further questions I would suggest posting in the staxrip thread since the author probably knows best about the command line parameters he has chosen for various presets.

Also, read the forum rules (#6) regarding illegally downloaded stuff.

[IbrahimKh]

edited
thanks
will try