[mythtv-users] VDPAU on older pre-G98 8400 GS

Frank Merrill fmerrill1 at gmail.com
Tue Jan 5 04:56:35 UTC 2010


On Mon, Jan 4, 2010 at 11:17 PM, Eric Sharkey <eric at lisaneric.org> wrote:
> On Mon, Jan 4, 2010 at 11:09 PM, Frank Merrill <fmerrill1 at gmail.com> wrote:
>> I think the real answer in the end is to just upgrade the card to
>> something more suitable to doing VDPAU at that resolution,
>
> That seems sort of silly.  The card runs acceptably when VDPAU is not
> being used.  I mostly only turned it on to see what all the fuss was
> about.  I was surprised that performance went from pretty good to
> abysmal on such a simple test.  I assumed that I must have done
> something wrong, which is why I was wondering if anyone on this list
> had direct personal experience with such a card.
>
>

Well, it's not really silly.  One of the primary purposes of VDPAU is
to move the decoding and deinterlacing from the CPU to the GPU.
If the GPU isn't as good as the CPU at doing that, then performance
would go down.
In your case by not using VDPAU, the card is just an output of the
stream, and may be fine for what you need.
I'll make an assumption here that your CPU has enough power to play
back the content without any issue.
This isn't an issue with VDPAU, it's an issue with your card not being
able to utilize that functionality well enough to make it worthwhile
to use.

If I turn off VDPAU my processor doe the work with an average
utilization of 40-50%.  With VDPAU, that drops to 4-5%.
I can then do other things with the CPU at the same time, like
transcoding or comflagging without getting any pauses during playback.
In many peoples case, using the CPU is fine, as long as it serves your purposes.

Frank


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