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GPU acceleration + h264 = more CPU load??

Posted: 01 Jun 2010 22:56
by krama
I'm currently running vlc 1.1.0-RC1 on windows 7 64bit but this "problem" also occured in previous versions (if gpu acceleration worked at all).

Whenever GPU acceleration is enabled and I play a x264 encoded file, I have a lot more CPU load than with it disabled.
Correct me if I'm wrong but I thought GPU acceleration should do the opposite??

I tried different files, one was even encoded dxva compliant but that didn't make a difference.
With HD resolution the CPU load is so high that >99% of the frames are skipped.
With SD resolution the CPU load is at about 30-35%, without GPU acceleration it's 5-10%.

xvid format plays fine, no difference in CPU load (or at least too small to measure).

relevant system specs:
core2duo e6300 @ 2.3ghz
ati hd3850 512mb
2gb ram
windows 7 64bit
vlc 1.1.0-RC1 (or previous "pre" releases)

Re: GPU acceleration + h264 = more CPU load??

Posted: 01 Jun 2010 23:05
by Jean-Baptiste Kempf
Yep, ATI issues. We are waiting for an update from ATI to fix their driver.