MythTV Power Consumption

… In which Eric discovers a simple way to reduce the power draw of his DVR …

When I built my new MythTV box, I did it with an eye towards power efficiency – both to save me a little money, and to maybe save the planet (hey, it’s just one thing, but it’s the little choices we all make).  So with that in mind, I got a 45W AMD 5050e processor, and Antec 80Plus EarthWatts 380W power supply, etc.  I don’t yet have any “green” drives in it; I’d hoped I could get the root drive to spin down to idle, but so far that’s been elusive.

Anyway, when all was said and done, I had a quiet box that idled at about 65W according to the Kill-A-Watt.  Not awesome, but a heck of a lot better than the old P4 heat plant that it replaced.

But one thing I noticed – when the menu was on the recorded shows listing, and the little preview was playing, power jumped up to around 80W!  And unfortunately, nobody ever exits from that screen, and it’s the one that MythTV returns to when it’s not playing.  So the box sat there for hours and hours decoding mpeg, bringing the cpu out of its low power states, and adding almost 25% to the power draw.  :(

It’d be nice if MythTV would just time this out, and go back to the main menu, or at least stop the preview playback – but you can just disable it in the frontend setup menus, for now.  Go ahead and do it – I bet you won’t miss it, and you’ll save a dollar and a pound of CO2 as well.

Oh, and an addendum: If you have the MePo theme (or other animated theme) running, even that adds to the power bill.  I modified the theme to drop the animations, and chopped another couple watts off the draw.

On edit… the MythTV Wiki has a page on power savings that I’ve updated too.