[mythtv-users] Power efficient backend-only server

[Vitani]

Good afternoon Greg,

Thank-you for your reply, I just have a few questions.

- If I'm running Nova-Ts, why would I not be running commercial skipping? I
am running it on all my recordings, and it *appears *to work (I don't
actually use a MythTV frontend, so I have never actually tried skipping the
adverts), is there something I don't know about the Nova Ts?

- Assuming I turn commercial detection off, would you agree that anything
over 800MHz (the slowest Atom) would be fine for recording & file sharing?

- Do you know if USB tuners draw less power than PCI ones?

- Does recording more than one channel at once make much of a difference? At
the moment I have the two tuners (on a single PCI card) set to record up to
3 channels each at the same time (to cover the over lap at the start/end of
two recordings on the same channel). Theoretically (although it's never
happened in practice) at the moment my set up could record six TV channels
at once.

Many thanks for your very detailed help with this! It's just what I was
looking for.


2009/10/20 <mythtv-users-request at mythtv.org>

> ---------- Forwarded message ----------
> From: Greg Cope <gregcope at gmail.com>
> To: Discussion about mythtv <mythtv-users at mythtv.org>
> Date: Tue, 20 Oct 2009 12:44:24 +0100
> Subject: Re: [mythtv-users] Power efficient backend-only server
> Hi,
>
> If you are running DVB Nova-T's I assume you are not doing Commerical
> skipping or transcoding.
>
> IF the above is correct, you need sod all processing power, just
> enough to cope with the IO (network or otherwise).
>
> Any atom based board/system would work fine (20w ish) (think nettop).
> Or a via based board (I use an SP13000 as a front/backend).
>
> To get a little over the top you will notice that the thermal (and
> hence power requirements) of systems these days are as much driven by
> their system board chip sets as the CPU - ie early atom boards had a
> low power cpu (5w?) combined with a heater, sorry, chip set that
> struggled to draw less than 15W.
>
> You can aim to get the board+disk to consume around 30W (20W for the
> system+cpu, 5w for each of disk+Nova-T YMMY).
>
> Thus do NAS'es - I believe (But could be wrong) that all the small
> NAS'es run linux or freebsd underneath.  Although you will find it
> hard to find, you need to be carefully about the power draw of a
> NAS/always on thingy - see below for my USB/ESATA enclosure power
> draw.
>
> To give you a benchmark my FEBE draws 60W and includes;
>
> SP13000 board+CPU
> 2xNova-T PCI cards
> 2x400 SATA drives
> 1x750 GB PATA drive
>
> Sadly the age of the chip set/OS release means it cannot do drive spin
> down as that would save another 15w average.
>
> I am planning a replacement with a Acer Revo (20w-30W), USB twin Tuner
> dongle (5w?), and a 1.5TB ESATA drive (5-7w).  This should drop to
> around 40W, less at idle.  Presently strugging to get my ESATA
> enclosure to draw less than 7w when the drive inside (1.5TB Samy green
> power) should only be drawing 4W (ie the transformer/chipset
> efficiency is rubbish at nearly 50%).
>
> Why am I so anal about this?  Simple - dropping 20W of continuous draw
> saves around £20 a year (at present prices), or £80 over a 4 year
> life.  Also lower power means low heat, low noise,  and hopefully
> better reliability (due to less heat issues).
>
> Greg
>
> 2009/10/20 Vitani <vitani-mythtv at tfxsoft.com>:
> > Good morning all,
> >
> > I currently have an old desktop PC running Mythbuntu (backend-only),
> using a
> > Nova-T 500, but it's big, loud, and relatively expensive to run. I was
> > thinking about getting a mini-itx motherboard (or smaller!), which used a
> > laptop hard drive, all in a nice small case, and pair that with a
> > Linux-based* commercial NAS (so should the MythBox die I can still access
> my
> > other media). That's the plan, but I'm not sure how much processing power
> a
> > backend-only system would need. There seems to be a lot of articles on
> the
> > Wiki about hardware, but most are out of date (they talk about version
> 20),
> > and/or focus on front-ends or both-end set-ups.
> >
> > I had a look on the PVR Hardware Database and only one entry really
> seemed
> > to fit what I was looking for -
> >
> http://pvrhw.goldfish.org/tiki-view_pvrent.php?systemid=Myth%20BackEnd%20Only
> > - but that set-up used a 2GHz Pentium 4, which I obviously would not be
> able
> > to run on my planned system.
> >
> > So my question is, has anyone created a backend-only MythTV system using
> a
> > small, power efficient computer, and if so, what components did you use,
> and
> > how well does it run?
> >
> > PS. If anyone knows of any commercial NASs which do run Linux, could you
> let
> > me know, as I've not found one yet.
> >
> > * the NAS doesn't have to run Linux, but I'd like to be able to set up
> > symbolic links from the NAS to the MythBox in order to access the
> recordings
> > directly over Samba.
> >
> > _______________________________________________
> > mythtv-users mailing list
> > mythtv-users at mythtv.org
> > http://mythtv.org/cgi-bin/mailman/listinfo/mythtv-users
>
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