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580 580
581\opt{archos}{\input{advanced_topics/archos-flashing.tex}} 581\opt{archos}{\input{advanced_topics/archos-flashing.tex}}
582 582
583\section{Optimising battery runtime}
584 Rockbox offers a lot of settings that have high impact on the battery runtime
585 of your \dap{}. The largest power savings can be achieved through disabling
586 unneeded hardware components -- for some of those there are settings
587 available.
588\opt{swcodec}{
589 Another area of savings is avoiding or reducing CPU boosting
590 through disabling computing intense features (e.g. sound processing) or
591 using effective audio codecs.
592} The following provides a short overview of the most relevant settings and
593 rules of thumb.
594
595\nopt{ondio}{
596\subsection{Display backlight}
597 The active backlight consumes a lot of power. Therefore choose a setting that
598 disables the backlight after timeout (for setting \setting{Backlight} see
599 \reference{ref:Displayoptions}). Avoid to have the backlight enabled all the
600 time.
601}
602
603\opt{lcd_sleep}{
604\subsection{Display power-off}
605 Shutting down the display and the display controller saves a reasonable amount
606 of power. Choose a setting that will put the display to sleep after timeout
607 (for setting \setting{Sleep} see \reference{ref:Displayoptions}). Avoid to
608 have the display enabled all the time -- even, if the display is transflective
609 and is readable without backlight. Depending on your \dap{} it might be
610 significantly more efficient to re-enable the display and its backlight for a
611 glimpse a few times per hour than to keep the display enabled.
612}
613
614\opt{accessory_supply}{
615\subsection{Accessory power supply}
616 As default your \dap{}'s accessory power supply is always enabled to ensure
617 proper function of connected accessory devices. Disable this power supply, if
618 -- or as long as -- you do not use any accessory device with your \dap{} while
619 running Rockbox (see \reference{ref:AccessoryPowerSupply}).
620}
621
622\opt{lineout_poweroff}{
623\subsection{Line Out}
624 Rockbox allows to switch off the line-out on your \dap{}. If you do not need
625 the line-out, switch it off (see \reference{ref:LineoutOnOff}).
626}
627
628\opt{spdif_power}{
629\subsection{Optical Output}
630 Rockbox allows to switch off the S/PDIF output on your \dap{}. If you do not
631 need this output, switch it off (see \reference{ref:SPDIF_OnOff}).
632}
633
634\opt{disk_storage}{
635\subsection{Anti-Skip Buffer}
636 Having a large anti-skip buffer tends to use more power, and may reduce your
637 battery life. It is recommended to always use the lowest possible setting
638 that allows correct and continuous playback (see \reference{ref:AntiSkipBuf}).
639}
640
641\opt{swcodec,disk_storage,flash_storage}{
642\subsection{Audio format and bitrate}
643\opt{swcodec}{
644 In general the fastest decoding audio format will be the best in terms of
645 battery runtime on your \dap{}. An overview of different codec's performance
646 on different \dap{}s can be found at \wikilink{CodecPerformanceComparison}.
647}
648
649\opt{flash_storage}{
650 Your target uses flash that consumes a certain amount of power during access.
651 The less often the flash needs to be switched on for buffering and the shorter
652 the buffering duration is, the lower is the overall power consumption.
653 Therefore the bitrate of the audio files does have an impact on the battery
654 runtime as well. Lower bitrate audio files will result in longer battery
655 runtime.
656}
657\opt{disk_storage}{
658 Your target uses a hard disk which consumes a large amount of power while
659 spinning -- up to several hundred mA. The less often the hard disk needs to
660 spin up for buffering and the shorter the buffering duration is, the lower is
661 the power consumption. Therefore the bitrate of the audio files does have an
662 impact on the battery runtime as well. Lower bitrate audio files will result
663 in longer battery runtime.
664}
665
666 Please do not re-encode any existing audio files from one lossy format to
667 another based upon the above mentioned. This will reduce the audio quality.
668 If you have the choice, select the best suiting codec when encoding the
669 original source material.
670}
671
672\opt{swcodec}{
673\subsection{Sound settings}
674 In general all kinds of sound processing will need more CPU time and therefore
675 consume more power. The less sound processing you use, the better it is for
676 the battery runtime (for options see \reference{ref:configure_rockbox_sound}).
677}