[mythtv-users] MythTV backend running on NVIDIA Ka-el, 35W replaced by

[Gary Dawes]

On 9 March 2011 06:07, Johan.van der Kolk <johan.van.der.kolk1 at telenet.be>wrote:

> On 03/09/2011 03:01 AM, Raymond Wagner wrote:
> > On 3/8/2011 20:28, mythtv wrote:
> >> The primary reason I want to reduce my power footprint right now is that
> >> my combined BE/FE sits below my TV and the fan is noticeably loud.  My
> >> current HTPC case is sadly limited in system fan options and my PSU fan
> >> seems to ramp to 100% (loud) at 55C.
> > Can you just move this machine to another room?  I've got my combo fe/be
> > in the basement under one of my TVs, and I just cut a hole in the floor
> > in the corner behind the TV to snake audio, video, and USB up through.
> >
> >> Intel Core 2 E6600
> >>
> >> Viewing content vs idle doesn't make any noticeable difference in power.
> >> I'm a little more surprised that recording 4 shows simultaneously only
> adds
> >> a few watts on top of the 85W baseline.
> > That E6600 should be dropping multiplier, and dropping the voltage to
> > match.  Unless you're using VDPAU for all your decoding and idling all
> > the time anyway, there should be a noticeable difference between
> > playback and idle.  Check /proc/cpuinfo when your system is idle, and
> > see what it thinks your clock speed is.  It should be something well
> > below the stock 2.4GHz.
> >
>
> I tested that, it hardly made a difference. CPU at 900MHz, all voltages at
> lowest possible. maybe 5W reduction, and noticeable performance impact.
> (same processor)
>
> >> After my RAID array had a failure I replaced a 3.5" drive with a 2.5"
> one
> >> and noticed about 5W less power.  So I moved everything except my 1.5TB
> >> drive to 2.5" disks as time and budget allowed.
> > A 2.5" hard drive may use less than half the power of a 3.5", however
> > three 1TB 2.5" drives will consume more than one 3TB 3.5" drive.  Make
> > sure you have your system set up to allow idle spindown.  An idling 3.5"
> > hard drive will consume 4-6W each, but ones that are parked and spun
> > down will be well under 1W.
>
> my new BE will be:
>
> ASUS P8H67-V (need three PCI slots for tuners) @ 125 Euro  (6.5W idle
> power)
> Intel I5 2400 @ 165 Euro (~20W idle power, 50W full load, they will not
> reach 95W TDP)
> 4 G RAM @ 46 Euro
>
> + 6 samsung 2TB drives in raid 5 or 6 (another 20W idle or 50W active
> total)
>
> + an 80+ bronze PSU Antec Earthwatts 380 or 450. (more powerfull PSU's
> become inefficient under the low load, even the 80+ gold models
>
> I needed a new BE, so cost was less of an issue. Energy efficient was a
> requirement though.
>
> This system should be efficient, but have enough reserve to do a couple
> of commdetects and transcodes while recording two to three programs
>
>
> Johan
>
> II have migrated my master backend to a Pogoplug device which is a low
cost, low power NAS device running Debian. The drives are mounted into usb
enclosures and plugged into the Pogoplug.

Mythtv installs directly onto it via apt and the debian multimedia
repository. It easily runs the database and master backend,

I have a combined slave backend/frontend in the living room booting via
netboot as it has the PCI tuners in, and a frontend upstairs again
netbooting. Drives are mapped via NFS.

My power consumption when the system is idle has dropped from approx 100W to
about 15W, and I estimate that the system is mostly idle for at least 8-10
hours per day.

two of the main reasons I went (besides saving money) for the pogoplug, was
that I wanted mythweb  availability when I am at work, or out and about (in
case I need to set something to record), and that wakeonlan was a lot more
reliable for me than ACPI wakeup on a single machine. I can add a torrent
server, home automation (just bought a telldus tellstick) etc to the
pogoplug....

Gaz
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