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diff --git a/manual/advanced_topics/main.tex b/manual/advanced_topics/main.tex index 47d4305f72..b13a76712b 100644 --- a/manual/advanced_topics/main.tex +++ b/manual/advanced_topics/main.tex | |||
@@ -580,3 +580,98 @@ current version. | |||
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 | } | ||