[mythtv-users] Superserver

Michael T. Dean mtdean at thirdcontact.com
Tue Aug 24 20:02:25 UTC 2010


  On 08/24/2010 02:51 PM, Mark wrote:
> Mark Hutchinson wrote:
>> Good point yes.
>> What might some good options be for small frontend machines be that 
>> can be turned off and on easily? I plan to have the frontends all in 
>> the basement as I have 3 CAT 6 cables run to each TV.  2 cat6 for 
>> HDMI and the 3rd for a remote or kb/mouse.
>> Does suspend work for this?  How would they be woken up?
>>
>> Thanks for the thoughts.
> have you considered mini-ITX atom boards for local frontends?  They 
> are very small and make no noise.
>
> Remote pc's and long wires are a pain, in case you have'nt played with 
> that yet...

OK, I'm not going to recommend any specific system.  Normally, I 
wouldn't even reply, but I'd just like to inject a bit of non-marketing 
reality into the thread.

Note, also, in the interest of full disclosure, I am a /confirmed/ 
Atom-hater.  I have a huge and deep bias against Atom.  (For some 
reason, I feel a computer should be able to compute.)

That said, low-power doesn't have to mean a toy.  See what proper design 
of a real computer system can do (whether you do it or Apple does):

http://www.apple.com/macmini/specs.html
http://support.apple.com/kb/HT3468

(10W idle and 85W max power consumption) and if you figure you'd be 
using VDPAU for decoding /when VDPAU works with the stream you're 
decoding/, you'd be running at close to that idle 10W even when 
decoding, for example, h.264 video.  The big difference, however, is 
that you actually have computing power in reserve when you need it (for 
Flash or video that doesn't meet the codec, profile, bitrate, and 
deinterlacing limitations of VDPAU or whatever other proprietary 
problems we can't solve).

Now, even if an ION system ran at 0W, and we assume the Mac Mini is 
running at close to idle when using VDPAU decode, that's a typical 
savings of only about 10W.  And, if you're shutting down your frontend 
when not in use, the difference between an Atom-based toy and a real 
computer in power usage is not a lot.  The difference in 
performance/limitations, however...

To put some numbers to it, let's use the preposterous assumption that an 
ION system runs at 0W under full load and the Mac Mini (or a system 
designed like it) runs at the full 85W all the time (under load or 
idle).  Further, let's say you shut down your frontends when not in use 
(as recommended above) and you use them for about 2hrs/day.  That means 
that the Mini is using 85W * 2hr (= 170Wh) per day.  That's 5100Wh/mo = 
5.1kWh/mo.  Assume a national average retail price of $0.12/kWh ( 
http://www.eia.doe.gov/electricity/epm/table5_6_a.html ), that's $0.612 
per month to run the Mac Mini/$0.612 saved by running an Atom system.  
Now, when you factor in the actual power usage (which will nearly always 
be less than--and likely /significantly/ less than--the 85W max), the 
Atom-based systems may not make much sense.  Basically, it comes down to 
some price between $0.0012/hr (at 10W consumption) to $0.0102/hr (at 85W 
consumption) to run the Mini--meaning the maximum savings you could get 
from running an Atom-based system is a penny an hour.

Basically, the saving from dropping your computer power usage from 170W 
to 85W is /much/ more important than the savings from dropping your 
computer power usage from 85W to 42.5W (even though in both cases, the 
power usage was halved).  When you get down to dropping from, say, 20W 
to 10W, there's not much savings involved.  (It's the same as fuel 
efficiency--trading your 10mpg vehicle for a 20mpg vehicle is much more 
beneficial than trading your 20mpg vehicle for a 40mpg vehicle.)

See, also, these (old) articles:
http://www.tomshardware.com/reviews/25w-performance-pc,2551.html
http://www.tomshardware.com/reviews/intel-e7200-g31,2039.html
http://www.tomshardware.com/reviews/intel-atom-efficiency,2069.html

I'm sure that there are newer articles using newer chips/architectures 
that do even better.  IMHO, Atom is a marketing ploy that allows Intel 
to charge significantly more while providing no advantages and only 
disadvantages.

OK, sorry.  I'm stepping down off my soap box, now.  I won't reply to 
this thread as I'm not trying to start a big war with Atom fans.  So, if 
some Atom fanatic needs to get the last word, feel free to reply, and I 
won't dispute anything you say.  If this post doesn't stand on its own, 
maybe it will at least get some people to think a little deeper about 
the issues--dig down beneath the marketing.

Good luck with your new setup, and I hope you find a way to reduce power 
consumption without losing capability.  And I'll reiterate that the 
/best/ way to do so is to shut down systems when not in use.

Mike


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