AVX2?

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gmb
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AVX2?

Post by gmb »

Here is a first preview for AVX2 @x264: http://de.scribd.com/doc/137419114/Intr ... ns-in-x264

Since Haswell adds AVX2 support very soon, is it planned to add AVX2 support for Handbrake?

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Rodeo
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Re: AVX2?

Post by Rodeo »

This will be in the nightly builds shortly, but most likely won't be in the next stable release.

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s55
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Re: AVX2?

Post by s55 »

When we bump x264 again itll bring in their AVX2 code. Just bare in mind the performance difference is pretty small.
I.e probably less than 10%

gmb
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Re: AVX2?

Post by gmb »

Better than nothing. Have you tested AVX2?

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s55
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Re: AVX2?

Post by s55 »

There are many other changes that will have bigger effect. Both in Handbrake and other libraries
You are essentially getting excited over marketing hype.

The x264 project is constantly adding new optimisations. You just dont hear about them because the tech news world doesnt normallymake a big deal about it. Its not something you really need to worry or care about.

Bare in mind also haswell is still a while away yet and anyone with access to it will be under nda.

gmb
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Re: AVX2?

Post by gmb »

So you didn't test, that's what I needed to know. I better wait for real tests to see what it brings or not. Don't worry, I give a s-hit about marketing.

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JohnAStebbins
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Re: AVX2?

Post by JohnAStebbins »

The x264 developers *have* tested and they usually say in their commit messages and/or newsletter how much each improvement gains. This time they were *very* thorough. http://www.scribd.com/doc/137419114/Int ... ns-in-x264

:oops:

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s55
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Re: AVX2?

Post by s55 »

Same link as the op john ;)

gmb
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Re: AVX2?

Post by gmb »

Does the nightly build support AVX2?

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s55
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Re: AVX2?

Post by s55 »

Nope.

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s55
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Re: AVX2?

Post by s55 »

X264 was bumped tonight so should be in tomorrows nightly.

Saying that, the current build already showed AVX2. Not sure if they didn't already have some level of optimization in there.

Either way, official numbers from x264 are 4~5% gain on AVX2 CPU's

gmb
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Re: AVX2?

Post by gmb »

Can I disable AVX2? I want to test on my machine what it gains from AVX2. Also power consumption test would be possible.

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s55
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Re: AVX2?

Post by s55 »

Use an older build without it.

It won't affect power consumption to any measurable degree.

gmb
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Re: AVX2?

Post by gmb »

HandBrake-svn5590_x86_64-Win_GUI.exe


Is this version with AVX2?

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Rodeo
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Re: AVX2?

Post by Rodeo »


gmb
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Re: AVX2?

Post by gmb »

Where I can download the last version without AVX2?

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s55
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Re: AVX2?

Post by s55 »

We don't keep a history of nightly builds so if you don't have a build, you'd need to build it yourself.

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