some ruminations on saving money, power, etc.

[dsr-mzpnVDyJpH4k7aNtvndDlA at public.gmane.org (Dan Ritter)]

On Thu, Sep 30, 2010 at 05:07:45PM -0400, Tom Metro wrote:
> Dan Ritter wrote:
> > Turns out that frequency scaling doesn't actually save power on
> > older Athlon chips (i.e. my main server).
> 
> Interesting. References? What's the cut-off (i.e. parts newer than X
> support it)?

All the mobile CPUs support it. Athlon desktops in generation K8
and later support it. If an earlier Athlon or Duron CPU doesn't
specifically mention Cool 'n' Quiet in the feature list, it may
be able to drop the frequency but the power consumption will
remain the same.

> > The Myth box is not particularly stable.
> 
> Do you have an idea why? My Ubuntu 8.04 LTS-based MythTV server isn't as
> stable as my Debian server, but it still generally has uptimes measured
> in quarters, rather than months or days.

Tuners. It's always something with tuners. I no longer use the
PVR500 board which would occasionally hang the machine, but the
FireWire connection is slightly flaky and I blame the STB.

> >> ...you'd need to build some software that queries the scheduler for
> >> upcoming recording times...then scheduling a wakeup task on another
> >> box.
> > 
> > ...the startup time is significant to anyone who
> > wants to watch tv at an unexpected time.
> 
> Oh yeah, I forgot about *watching* TV. :-)
> 
> 
> >> Have you considered consolidating your main and MythTV servers? (I hear
> >> some people have even had success running MythTV in a VM.)
> > 
> > The idea fills me with dread.
> 
> Do you use the live TV feature? If not, maybe a blended solution would
> work...

No, we never watch live TV. There's only one day a year where we
might want to do that (it's a Sunday in late January, usually)
and I've tended to use the TiVoHD for that.

> First, spin off your MythTV storage to your main server or a low-power
> NAS appliance.

...triggering a need to buy a gigabit switch. Currently the house runs
pretty well with two FE switches, one upstairs and one down. Recording
five HD streams and playing back three (current max) will certainly eat
that all up and ask for more.

...triggering a need to re-do storage. Currently I have just
under 6TB in use; I think I'd need to go to 4 2TB disks, which
won't fit in the existing main server case, so...

> Then run a MythTV slave server in a VM on the main server. This slave
> would be stripped down and used only for serving up recordings.

Possibly triggering a RAM upgrade on the main server :)

-dsr-

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