old laptop as core, aiming for low power usage?

[Philosophy]

.. I have a lot of noob questions <== the 3 important ones are:

1) Is there an advisable/preferred way to make a low-watt system? 
2) If HDTV capture is possible on a non-core node, what CPU-intensive work does a stand-alone Core do? 
3) When copying from CDs / DVDs / HDTV, doesn't the applicable Media Director do most of the work?


I'm learning LMCE; the wiki/FAQ leaves me wondering about hardware requirements and total power usage..  To minimize always-on wattage, I'm tempted to use an old laptop (Centrino era) as the core, and an off-the-shelf NAS (with power saver feature) for storage.  (The laptop's battery might also serve as a convenient UPS.)  But it's unclear to me how much/little the core is used when media is served from the NAS to the MDs.  Does core mount the NAS locally, such that all media served by core effectively passes through the core's network card twice? .. Is there a way to tweak the NAS to bypass the core, or perhaps paticular network hardware to prevent bottlenecks?


------------------------------------What follows are my noob config plans

I'm hesitant to give up a segregated home LAN--especially if there is risk of hardware failure on an old laptop.  Does the LCME community have any tricks for limping along with a temporary DHCP server when their core goes out?  (Or is it wise to have an extra home router at hand?) 

My attempt to plan a "slow core" configuration is below.  I suppose the big workstation could have a third network card, so it could also act as an MD.  (I find it convenient to keep a slow wifi router open, for less hassle--and also for speed if/when a legacy 11b device appears)

internet -> LAN on home gigabit router:
> NAS device w/ power save & dual gigabit ethernet
> big, power-hungry ubuntu workstation for photo & home video work, Win7 virtual machine.  Hardware powered down when not needed
> LinuxMCE core laptop
> networked printer (maybe via NAS)

"big workstation" has a second network card
> bandwidth-limited open wifi (802.11b/g), internet only
---| guest's devices
---| older home devices (Wii, laptop, etc)
(be nice to neighbors, but somehow put a max on bandwidth to limit the effect of leeches.  Power off this router when the workstation is off.)

LinuxMCE network, behind core's eth1 > small switch (no dhcp)
> NAS device*
> fast, encrypted wifi (802.11n) w/ dhcp disabled
--| LinuxMCE media director(s) with modern hardware**
--| LinuxMCE orbiter(s) (apple iPad)
--| general use laptop
--| other home n-capable and encryption-capable devices
--| (maybe) big workstation's eth2


* NAS device w/ dual network ports.  Several manufacturers make dual-port NAS, some of them actually use the term "multi-IP"  ... so I guess it'd work, being on both sides at once?

** modern hardware = fast/wide processor for encoding, tv capture, nVidia vdpau card, hoity toity sound


.. thanks for reading, appreciate any comments

[JimmyGosling]

I'm going to admit up front that I have not thoroughly read your post, but I think I get the gist of it.  Correct me if I'm wrong.

-You want to conserve energy on the core by using a laptop instead.  I wouldn't advise it.  For starters, I'm not sure if you have a laptop with two network devices, but if you did and you're serving up movies you'll likely see some tearing (audio/video out of sync) and multi room would be even less likely.  As for the batter backup, having your core running isn't going to do you much good without a network switch or anything else with power.
-If you want to conserve energy at the MD level, look at a eee box or a revo.  super small and they consume very little (possibly even less than your laptop considering they don't have a monitor or cd rom of their own)

-backup network.  I have a top level router with 4 ports on it, which comes down to the core whoch goes down to it's own 24 port switch.  I've had times when the core wasn't working, but I wanted all those computers below the core to still be usable on the network.  Since I have a patch panel built I switch the line that would be running from the core to the large switch to now come off the router.  Everything runs great.

Hope that helps.