Power Usage

From AwkwardTV
Revision as of 04:58, 17 September 2007 by ZgzA26 (talk | contribs)
Jump to: navigation, search

san martino del carso dentista orologi da muro altoparlante coppia amatoriale papa wemba musica internacional elo ultimate collection carrera 4 s brucespringsteen origine cognomi bilancia digitale per neonati foto di tagli di capelli motorola d470 touch me tease me einstein dr dj the album megamix 2004 un pilota ritorna antoinette van dijk djlover carosone video bomboniera fai da te hp psc 2610 je veux une femme like u rasmus guilty dottori ortopedici targui progdvb porte cabine enel frenkie film gioco di donna gallerie di sesso lina volonghi il pene piu lungo e spesso immagini e313 usb lo chiamavano mezzogiorno mari land la collana della regina qtek 8010 tom tom diana spencer cpu amd athlon xp eduardo de crescenzo tim it i box wap gel elettrodi whiplash hp pavilion athlon 64 manlio tefal kaleo dominio secondo livello live soccer siemens gigaset c1 lascerai scheda video sapphire radeon 9550 256mb rullo fusore lampadine led la via della droga il paradiso dei fuorilegge mazzucato kit wireless netgear la ragazza sotto il vetro the day after il giorno dopo soluzione spyro militari org la verita su maria defilippi www caturano it bertram ernst olidata lcd tft 19 www comune fe it buena vista nikon af s dx 55 200 acer bluetooth gps integrato traduzioni latino gratis syndicate of low rio carbon pearl jesse capelli stampante hp deskjet foto di ragazze obese sony vgnfs215z buddy miles changes areaprivati barby girl foto yuma models enermax alimentatore eos d 60 web cam palestre severina vuckovic configurazione cover neffa fi abbigliamento dolce e gabbana postalmarket thrustmaster firestorm dvd denon melissa b pazi s kime spavas dsp arezzo un atimo di pace ottico 3 michael bergin giustizia per gli indios you ll never be alone konica minolta dimage z5 silver ragazza sevilla t610 giochi java d 730 hotel a mestre studio zeta kochanowski piotr deck the halls linguistica generale berruto driver usb holliwood samsonite hardlite fabriano copy 1 modem adsl con usb ethernet ventole case 120 te deum babbo natale sulla neve sexo porno nikon coolpix 7 1 meliso le avventure di oci indesit wi 600 sonds yakumo tft 17 xj guta si sorina samsung 32 crt suggest link listen to holding out for a hero by bonnie suoceri gay image sexy sexy naked images for nancy agram il re leone si avvicina milto spa cavo a620 ddr vdata silvesterkonzert 2000 giuseppe verdi golf2 pony express lucia valerio bull terrier burgman 650 suzuki fuji s5500 teckno processori prezzi carabinieri prima serie vol 2 noleggio auto torino psicometrico bifid banda calipso tommy e carolina amore bdsw produzione pellet durand le temps des cathedrales wireless microfoni cd giorgia lazov corriere sport it lost highway alcamo tp singole rizzi porte kristin gioco al giorno isaak xcam support esa fish kens labyrinth hard top boxster saunders uomini senza paura copertina convivendo cioffi ida cd festivalbar blu e rosso il rodeo pompa per liquidi masterizzatori dvd esterno usb firewire programmi per chat lotus esprit 22 turbo easy share le persecuzioni degli ebrei palmare con fotocamera tomtom 5 volo marseille locali scambisti in lombardia feast rivenditore h3g cucinare in ristoranti videoproiezione accessori cant wait till tonight video divertenti rimini live cam o di una pianta di casa unifamiliare tip excel 2002 oltre ogni limite libri escuz moore catherine lucille ami ia hp videoproiettore le iene compilation delblanc sven piatto porcellana wresteling loughborough home theatre technics joypad play station pacchetto viaggio lettori dvd vhs le amanti del dottor jekyll video scandalo a luce rossa the red star in una galleria fotografica scaldabiberon casa auto chicco mutuo migliore ostaggi curs mare italia toscana cartella portablocco armani jean pallacanestro pooh dove sono gli altri tre push up midi file villaggio nuraghe le preposizioni italiane libri levi se questo e un uomo serenata toto cutugno schede madri con chipset ati cross word web camera spiagge riccione kyocera fs c5020n ati radeon 32mb g4 ibook assistenza sansui schweinfurth georg august sexy old woamn vietnam music joypad wireless xbox cuore zingaro tv flat 37 chuci fia gt gold miner vegas play now televiewer 1600 gobbo == Measured power usage == Measured with Kill-A-Watt, 119V input, tested with 720p output to LCD (not plugged in to wattmeter)
Note: These figures have also been confirmed with a 240V unit.

  • Main menu: 14-15W
  • Playing a 640x480 XviD file: 17-18W
  • dnetc -benchmark2: 20W
  • "Sleeping" (white light off, no video output after holding down Play button): 14-15W
  • After a "shutdown -h now" command: 15W

Questions

  • Is there any way to further reduce power usage, e.g., disabling the graphics processor?
  • Perhaps swapping out the hard drive for a flash based card like is being done with iPod Minis nowadays?
  • What about a "Shutdown" frappliance that physically turned it off. (Realising that some sort of hard power switch would probably be needed to turn it back on).

Also as much as 30% of the power could be used by the AC-DC transformer, running straight from DC could lower the amps used.

pmset

  • Doing a pmset -g yields:
-bash-2.05b$ pmset -g
  System-wide power settings:
     SleepDisabled          1
  Active Profiles:
     AC Power                -1*
  Currently in use:
   disksleep      15
   hibernatemode  0
   displaysleep   1
   powerbutton    0
   sleep          30
   autorestart    1
   hibernatefile  /var/vm/sleepimage

So it looks like sleep has been "disabled" in the sense of traditional mac sleep. I am not super adept at the pmset command, and can't seem to find a way to reverse that setting. You are able to play with the settings currently in use (setting disksleep to 5, or 10 for example), but trying to set womp gives no results. A pmset -g cap gives you:

-bash-2.05b$ pmset -g cap
  Capabilities for AC Power:
    displaysleep
    disksleep
    sleep
    autorestart
    powerbutton

Additional, you can directly edit the file: /Library/Preferences/SystemConfiguration/com.apple.PowerManagement.plist. At the bottom is the setting for SleepDisabled, which is set to true by default.

Note: I just changed the file so SleepDisabled is false, saved changes and rebooted. The settings were saved, and now I will see if the system goes to "sleep" on its own. I'll also report back if the AppleTV cools down at all, or if it appears the hard drive has spun down.

I have tried SleepDisabled false, but I doesn't help. The consumption is always 14-15W when idle or "switched off".

On the other hand if you "switch off" the Apple TV by holding play/pause key for 5 seconds and then you look at pmset -g there will be

   disksleep      1
   displaysleep   1

while in normal state there are zeros. The harddrive seems to sleep (I feel a delay issuing commands in commandline), but the consumption stays the same 14-15W :(

Measurement Requests

  • Power supply efficiency
    • Efficiency is measured as effective output power divided by input power (Po/Pi x 100 %). Pi can be measure as above using a Kill-A-Watt meter (you should take the Pi measurements at the same time as you measure the DC output current). To obtain Po (recall that Po = VI), first measure the DC output voltage (V) of the supply using a multi-meter in parallel with the output supply (this value should remain relatively constant regardless of what function the AppleTV is performing). Next, measure the DC current (I) using the multi-meter remembering that the meter must be placed in series with the DC output voltage from the power supply for this measurement (the output current will vary with what function the AppleTV is performing - current is proportional to processing load). Then, the output power (Po) is computed by multiplying the measured DC voltage by the measured DC current (Po = VI).
  • The digital wattmeter I have can measure P and U*I. If I remember well P=U*I*cos phi, where phi is the phase and cos phi is the efficiency. For AppleTV I have measured in idle P=15W and U*I=31VA, the efficiency seems to be comparable with my laptop power supply, where I have P=30W and U*I=60VA.