Now that the transmission torrent app is out (and working well for me on n800 / OS2008 beta in first tests), I realised that this could be a great way of saving energy vs. keeping the laptop on for a couple of hours.

Without a watt meter in the house - do you know how much watts an N800 draws while downloading files via Wifi in this way? My Lenovo n200 laptop might be around 50W in energy saving mode, I guess (the power brick is rated at 90W), so the potential is definitely there.

Just curious if someone has measured power consumption and has a rough ballpark figure. Thanks!

(P.S.: Looking at the ecological picture holistically, the whole internet infrastructure for delivering the file of course draws a constant amount of energy - potentially multiple times what I use on my client. Also, not the entire swarm will use energy-efficient devices. Still, it's a start!)

Don't forget you'll need to leave your N800 on charge, unless the torrents magically download before the battery goes flat. Also, once complete you're going to need to copy it to a PC.

Take the battery's rated capacity, time how long the N800 lasts before being charged. Use some basic physics/maths to work out the energy used. Then do the same for the mains charger.

I personally don't see the point in a torrent client for the N800. It falls into the "because we can" category in my head, along with Apache and Wordpress. Clever technological feats, but ultimately only useful in a few very specific applications.

After all, the Ubuntu DVD iso (and other legitimate uses of Bit Torrent technology - transferring huge files) is 4.3GB which won't fit onto most people's memory cards, and what's the point of "evaluating" a film that won't even play on the device without being copied to a PC, transcoding, and copying back?

I think you could save more energy by doing other things in your home - turning down the heating a bit, not running really deep baths or standing in the shower for an hour, etc.

Incidentally, the OS2008 beta now reminds you to unplug your charger from the mains to save energy, which I thought was a nice touch

I suppose you could get a solar charger and run your N800's charger from sunlight, effectively making it cost zero to run

Thanks, Piku, for giving your view. I partially agree with the use case for an tablet torrent client being slightly underdefined at the moment.

However:
- an 8GB SDHC card can hold smaller downloads, and they just dropped in price significantly (sub-50€ in Europe).

- there's stuff available you can use on a tablet well without transcoding (some music files, PDF documents, video encoded for mobile).

- you could probably hide most of the complexity from the user and use the technology to distribute Maemo download application files or legal media downloads.

Well, this was supposed to be a thread about saving energy - Nothern Germany is not the best place for long hours of sunshine, so the solar charger idea is not quite feasible. My tablet sees a lot of inhouse (couch) use, so I might as well use it as a laptop replacement to save on energy for downloads.

n800 battery capacity: 3.7V * 1500mAH = 5.6 WHr
If transmission runs for 3h on one full charge, it'd run @ 1.8W
If it runs for 5h on one full charge, it'd run @ 1.12W

Does anyone have a better rule of thumb-ish calculation (or want to correct my math)?

If i had to guess, id say around 2-3 watts. I'll try to verify tonight using a watt meter. -Update- hard to verify measure... at first while the battery was being recharged it peaked to 5 watts... that would be max. After that it settled down to 0-1 watts for pretty much the whole time of downloading a 350mb file with screen lit. I might try to retest with battery out later to ensure full load is on ac.

As for use cases, the nokia can pull down standard 350mb xvid tv shows or 700mb movies and play them quite well with mplayer... no need for pc or slow usb transfers. True though that most arent legal so you could wait for some 'official' drm-laden version Its a good step towards being a self sufficient pmp (already is for me)

Thanks for looking into it pipeline! The tablet seems to be is quite efficient - and the screen could even be turned off if it were just sitting there downloading something.