x264 CPU usage

[Tomdarkness]

Hey,

I've been searching around regarding x264 not utilizing 100% CPU and apparently it is not receiving the input frames fast enough. However, most of the solutions point to having some processing filters that are causing the bottleneck but I'm not doing any processing - just straight encoding the footage to H.264.

I am trying to encode fraps footage (i.e quite large files) to 1080p H.264 using x264. The problem occurs regardless of what program I use (I've tried VirtualDub and Sony Vegas) and the CPU only hovers around 25-35% with the encoding running at around 10fps. I have a 3930K (overclocked to 4.65ghz) and have set x264 to use 12 threads.

It is not being limited by the hard drive as I can run 3 simultaneous encodings from the same drive to get the CPU to hit around 90% CPU.

Does anyone have any idea what may be causing this?

Thanks :)

[Atak_Snajpera]

post your command line

[Asmodian]

It sounds like the fraps decoder you are using is single threaded and is your bottleneck. Do you have any cores maxed or close to it?
:script:

[GEfS]

Use Avisynth MT and set threads=18 or =0 (automatic detection)
Threads=12 is not maximum. Because x264 threads always multiple 1.5 times.
Your CPU is 12 threads, so max threads in x264 must be 18.
Post your Avisynth script, x264 command line here.

[Asmodian]

If the decoder is single threaded using Avisynth MT will not change anything.

[detmek]

I don't know if FRAPS propriate decoder is multithreaded but FRAPS decoder in LAV Video is and it can be used with DirectShowSource() or DSS2() if Haali is installed. Well, it is on my Athlon X2.

Edit:
FRAPS VFW decoder is single-threaded.

[Blue_MiSfit]

This definitely sounds like a decoder bound issue. I'd try the above suggestion to use the LAV decoder.