[mythtv-users] Power usage and CPU/GPU combo chips (was Re: 0.25 VAAPI does it work)

Michael T. Dean mtdean at thirdcontact.com
Sun Oct 14 23:21:50 UTC 2012


On 10/11/2012 07:54 PM, Michael wrote:
> On 10/11/2012 04:09 PM, Michael T. Dean wrote:
>> On 08/07/2012 12:32 PM, fred watt wrote:
>>> NVidia is an option this is easy to to setup with VDPAU - but it means
>>> another card in my frontends for me (a) want to keep as low power as
>>> possible
>>
>> This is often mentioned, and I have to wonder about it.  It seems to 
>> me that any "sane" design (in this world where AMD/Intel know a thing 
>> or 2 about gating--more, it seems, than a certain company that makes 
>> a quad-core ARM chip with 5 cores because they couldn't work out 
>> separate per-core gating, so it uses either the one-core or the quad 
>> core chip at any given time :) for a ceepie-geepie (CPGP, or CPU + 
>> GPU, or APU, or ...) would completely shut down power to the on-chip 
>> GPU when you disable it.  In that case, you'd disable the onboard GPU 
>> (and save whatever number of watts it normally draws at idle) then 
>> add back in a PCIe (or whatever) GPU that draws some 6-10W at idle (I 
>> think the GT220 was 7-9W and the GT430 was like 6-8W, IIRC).
>
> I don't know how it works or doesn't :)
>
> But I have a i5 with built in video.  Using the onboard GPU the whole 
> system takes 35+ Watts playing back video.  If I add a GT430, the 
> system now takes 85+ Watts.

You mean during playback (seemingly with the video card heavily 
loaded--as the GT430 has a TDP of 49W (and you're seeing a 50+W 
difference).  In theory, though, it wouldn't be heavily loaded much at 
all (maybe during playback--though I don't think that's much of a load 
on it?), and it does idle at 7W (according to 
http://www.anandtech.com/show/3973/nvidias-geforce-gt-430/17 ), so you 
shouldn't be seeing a 50+W difference just from adding the card.

Mike

Mike


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