[mythtv-users] System specifications review...

Patrick Doyle wpdster at gmail.com
Mon Nov 16 18:15:23 UTC 2009


On Mon, Nov 16, 2009 at 12:37 PM, Yeechang Lee <ylee at pobox.com> wrote:
> Patrick Doyle <wpdster at gmail.com> says:
>> So if I go with this processor, which I selected based on reports of
>> it's idle and max power consumption (6.8W and 31W), is there any point
>> in adding a VDPAU graphics card later?
>
> Yes.
>
> Let me reword that: No matter how much CPU horsepower you have, there
> is no point in *not* getting a VDPAU-capable card *now*. For $30-50,
> how can you lose?
I could lose if it increased the overall power consumption of my box.
That one could be tough to measure, as there is a certain "idle" power
consumption that, almost certainly must be higher just by adding a
card to the box.  But that would, ideally, be offset by the total
reduction in power of using the VDPAU decoder instead of using CPU
cycles.

Hmmm... as I think about this more, it occurs to me that it is more
complex than I first thought... after all, when I turn off the TV, the
MythTV box is likely to stay powered on, still tuned to and displaying
whatever channel it was last tuned to and displaynig.  (At least
that's the mode that my family and I have been trained to expect from
the TiVo.)  Therefore, the so called "idle" power consumption could be
lower with a VDPAU-capable card, just because it would (hopefully) be
more efficient and decoding the OTA video than the CPU would be.  Of
course, if we change our habits such that the default screen is the
menu screen and we never watch live TV through the Myth box, then the
the idle power would (presumably) be much lower.

I could lose if the fan on the card made the box too noisy.

I could lose if I put in a card that is underpowered for HD.
Right now, all I know about VDPAU is that I need a card with a certain
capability if I want to use "Advanced (2x) Deinterlacing".  I'm not
even sure what "Advanced (2x) Deinterlacing" is, except that it is
probably better than "Advanced (1x) Deinterlacing".  I don't even know
if I could tell the difference between 1x or 2x deinterlacing, nor do
I know if I might possibly prefer the 1x deinterlacing.  But I do know
that the higher end cards all seem to support it.  So, in order to
maximize my options, I'm inclined to go with a higher end card -- i.e.
one that would probably consume more power, dissipate more heat, and
therefor require more airflow than a lower end card.  Round and round
she goes...

--wpd


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