Re: [gentoo-user] PCI video cards, hardware accel, upported by open-source drivers?

[Michael Mol <mikemol@gmail.com>]

On Sun, Apr 15, 2012 at 4:45 PM, Volker Armin Hemmann
<volkerarmin@googlemail.com> wrote:
> Am Sonntag, 15. April 2012, 16:44:43 schrieb Florian Philipp:
>> Am 15.04.2012 16:22, schrieb Michael Mol:
>> > On Sun, Apr 15, 2012 at 10:09 AM, Florian Philipp <lists@binarywings.net>
> wrote:
>> >> Am 15.04.2012 15:18, schrieb Walter Dnes:
>> >>> On Wed, Apr 11, 2012 at 06:30:02PM +0200, Volker Armin Hemmann wrote
>> >>>
>> >>>> Am Mittwoch, 11. April 2012, 02:11:35 schrieb Walter Dnes:
>> >>>>>   If it's PCIe, so be it.  Actually, a post that prevents me wasting
>> >>>>>
>> >>>>> money is helpful <G>.  Would PCIe be significantly better on the same
>> >>>>> CPU+GPU, or is it hype?
>> >>>>
>> >>>> a lot, lot lot lot better. No hype.
>> >>>>
>> >>>   I've done some looking, and I'm back with more questions.  I've also
>> >>>
>> >>> read the Nouveau-versus-NVIDIA thread.  Questions...
>> >>>
>> >>> 1) Will PCIe 2.0 cards work in a PCIe 1.0 slot?  I'm not expecting 2.0
>> >>> performance, I just want full backwards compatability.  PCIe 1.0 cards
>> >>> seem to be rare, and have to be ordered online, while I can pick up a
>> >>> 2.0 card locally at a store.
>> >>
>> >> PCIe-2.0 is fully downward compatible to 1.1 and 1.0.
>> >>
>> >>> 2) My main "torture test" will be HD fullscreen video.  Will there be
>> >>> major improvement in that?  That's 2D.  Forget 3D.
>> >>
>> >> 2D video is still rendered using OpenGL if your video player supports it.
>> >
>> > I'm not aware of any video decoders using CUDA, OpenCL, or pixel
>> > shaders for video decoding; AFAIK, unless you're using VDPAU you're
>> > still using the CPU to render the video to a frame buffer. The most a
>> > video player is going to use OpenGL for is stretching that frame
>> > buffer to fit a window or screen, and possibly as a compositor to
>> > place overlays like subtitles or playback control elements..
>>
>> Agreed. Decoding is still usually done in software but offloading
>> scaling and YUV to RGB conversion helps none the less. Mplayer, for
>> example, allows a lot of customization depending on the amount of
>> texture units. With high resolution displays and slow CPUs, this can
>> have surprisingly large effects.
>>
>
> and with vlc you can use vaapi which can make use of the video decoding engine
> of the graphic chip.
>
> If the movie is using the right codec, of course.

Also depends on whether or not the graphics driver and vaapi like each
other. I'm not aware of NVidia cards supporting VA API yet.

VA API is pretty new; it'll be interesting to see where it goes, and I
hope it takes hold. Right now, the most tested and working solutions,
AFAIK, are nVidia cards and VDPAU. At least, that combination has been
working well for me for 3-4 years.

-- 
:wq