<html>
<head>
<meta content="text/html; charset=windows-1252"
http-equiv="Content-Type">
</head>
<body text="#000000" bgcolor="#FFFFFF">
Hi Priya,<br>
<br>
I originally wrote this to the x264-devel list, but it didn't seem
to work repeatedly. So now I decided to forward it directly to your
email address:<br>
<br>
Regarding the prevalence of Power8 vs. Intel x86/x64 architectures I
can only emphasize what has already been said here.<br>
<br>
However, as we have gone through the x264 build process for several
Power MCUs in the past:<br>
<br>
Did you make sure that x264 was actually build with Altivec support
enabled? For some platforms we had to adapt the configure script
accordingly.<br>
<br>
Of course a missing Altivec support can't entirely explain the
difference between x86 and Power performances, for reasons as
already mentioned by Janne. But also on newer Power core
architectures the legacy x264 Altivec code can quite make some
difference.<br>
<br>
Having said that: We also did some x264 performance benchmarks on a
current Freescale/NXP T4240 Power CPU (24 e6500 cores available)
with Altivec support enabled. Up to a parallelization of 8 to 10
threads you get some performance benefits with each additional
thread on this platform. Beyond that parallelization grade you see
quite significant performance saturation effects - presumably due to
Altivec resource and CoreNet bandwidth limitations.<br>
<br>
Cheers<br>
<br>
Philipp<br>
<br>
<div class="moz-cite-prefix">Am 20.01.2016 um 08:16 schrieb Priya
Duggirala:<br>
</div>
<blockquote
cite="mid:201601200717.u0K7H2lB019961@d01av03.pok.ibm.com"
type="cite">
<p><font size="4" face="Calibri">Performance of x.264 codec with
FFmpeg on ppc64le is 30%-50% slower than on x86(Intel). This
is in contrast to what is expected on Power8/LE. The x264
codec needs to be further optimized for Power8/LE as there is
signification performance degradation on POWER. Attached are
the test results for FFmpeg+x264 codec.</font><i>(See attached
file: status_enabled_ppc.txt)</i><i>(See attached file:
status_enabled_x86.txt)</i><br>
<br>
<font size="4" face="Calibri">FFmpeg was compiled as:</font><br>
<font size="4" face="Calibri">./configure --enable-gpl
--enable-memory-poisoning --enable-avresample --enable-libx264
--extra-cflags=-I/usr/local/include
--extra-ldflags=-L/usr/local/lib</font><br>
<br>
<font size="4" face="Calibri">x264 codec is compiled as:</font><br>
<font size="4" face="Calibri">./configure --enable-shared
--enable-static --enable-debug</font><br>
<br>
<font size="4" face="Calibri">Run time options used:</font><br>
<font size="4" face="Calibri">perf stat -o perf.log ffmpeg -i
VanillaCakeRecipeDemonstration-Joyofbaking.com.mp4 -vcodec
libx264 -acodec aac -strict experimental -threads 0 -level 31
-r 30000/1001 -b 1900k -pix_fmt yuv420p -tune ssim -profile
high -vf setdar=16:9,setsar=1:1 -x264opts
stats=x264_00_2pass.log:bframes=4:b-adapt=0:b-bias=20:b-pyramid=normal:ref=1:partitions=all:direct=auto:me=umh:merange=12:subme=9:trellis=0:no-fast-pskip=1:no-dct-decimate=1:fps=29.97
-f mp4 -y /dev/null</font><br>
<br>
<font size="4" face="Calibri">Machine Configuration : </font><i>(See
attached file: Machine Configuration.txt)</i><br>
<br>
<font size="4" face="Calibri">Regards,</font><br>
<font size="4" face="Calibri">Duggirala Priya</font><font
size="4" face="Calibri">.</font><br>
<br>
</p>
<fieldset class="mimeAttachmentHeader"></fieldset>
<br>
<pre wrap="">_______________________________________________
x264-devel mailing list
<a class="moz-txt-link-abbreviated" href="mailto:x264-devel@videolan.org">x264-devel@videolan.org</a>
<a class="moz-txt-link-freetext" href="https://mailman.videolan.org/listinfo/x264-devel">https://mailman.videolan.org/listinfo/x264-devel</a>
</pre>
</blockquote>
<br>
</body>
</html>