whack x264 performance overclocked core i7

[mikemodano9c]

anyone that do x264 encoding notice that when doing any two pass with x264 usually less than 50% of the cpu's 8 threads are used?

i can run that techarp x264 benchmark and it flies at about 100fps on the first pass and 36fps on the second doing a 720p conversion from mpeg2 to x264...

i'm using ripbot264 and the first pass is crawling at around 30fps on the first pass...WTF....

the second pass is using 100% of the 8 threads so at least that is good...

 

[Snowknight26]

So first you claim that it uses less than 50% but then you say it does 100%. Need to be more specific.
Don't use a GUI, post your command line, and post your avs if you're using one.

 

[jonniefive]

So first you claim that it uses less than 50% but then you say it does 100%. Need to be more specific.
Don't use a GUI, post your command line, and post your avs if you're using one.

Actually, the OP said the FIRST pass in a two-pass encode is where the issue, 50% CPU usage occurs and that the second pass uses 100% as it should.

I don't have an i7 core, but I have this issue when using handbrake for x264 encodes occasionally.

 

[criccio]

The first pass is usually around ~50-60% CPU usage for me, then pegged at 100% for the second pass.

 

[Snowknight26]

Actually, the OP said the FIRST pass in a two-pass encode is where the issue, 50% CPU usage occurs and that the second pass uses 100% as it should.

First, he did say 'any two pass', not clearly specifying which pass on a two pass, tying into my second point.

2nd, 30fps, let alone 100fps, on a 1st pass?! That's way too fast for a first pass unless you're using the worst possible settings, ih which case you shouldn't even be using x264. -.-

3rd, it depends on the settings. Sounds like --b-adapt 2 is being used for the first pass, which unfortunately doesn't have multhtireaded lookahead, hence low CPU usage. If you go back to using --b-adapt 1 (which I advise against.. but I guess it doesn't matter inthis case as it seems like you're using fast, not quality settings to begin with), CPU usage should increase quite a bit.

 

[TehQuick]

It's also possible that in first pass, the extra HT threads are NOT used... hence 50% usage

 

[Snowknight26]

Doubt it. Default thread count for x264 is cores is 1.5*cores, so if you have a quad core with HT, 8*1.5=12.