From: Jens Arnold <arnold-j_at_t-online.de>
Date: Mon, 26 Jul 2004 00:44:35 +0200

>> 2. What benefit will this have? I assume battery time, but it
>> doesn't seem like a great saving to me. Has anyone performed
>> any calculations that might determine the possible battery
>> time increases?

> Jens is currently measuring this. We have ~10% more buffer, so
> the saving can only be in that order of magnitude. Not too
> much, but if it comes for free...

I completed my first set of runtime tests - 2 passes each for mp3
playback and video playback, both from ROM (Rombox) and from RAM
(RoLo'd into .ajz compiled from the same .cvs tree).

Of course, doing only 2 rounds and then comparing small
differences is rather unreliable from a statistical point of
view, but I can say with some certainty we can expect ~3..4%
longer runtime when running from ROM with standard RAM (2 MB).
For those who did the 8 MB mod it will be less...


Some more details about my tests for those who are interested:

Device: Archos Jukebox Recorder 20 (V1, USB2), upgraded to
            80 GB (IBM (HGST) IC25N080ATMR04)

Batteries: Stock Archos 1500 mAh NiMH

Rockbox: CVS tree of 2004-07-21, .ajz and Rombox versions, only
            other modification being my "geeky" bitswap (shouldn't
            have noticeable impact on battery performance; saves
            some code space)

Settings: (only settings that might have some influence on
            battery runtime while the test is running)
            Disk Poweroff: Yes
            Max files in dir browser: 300
            Max playlist size: 5000
            Caption backlight: No
            Scroll speed: 8 Hz
            Peak meter/Performance: High performance
            (there is a peak meter in my .wps)

MP3 test: Collection of VBR mp3s (a whole album), average
            bitrate 227 kbps; played with Repeat: All

            ROM runtime: ~9:00 h
            RAM runtime: ~8:45 h

Video test: 3:12 h of Movie converted to .rvf with mp3 audio
            track, total average bitrate 626 kbps; manually
            restarted at the end

            ROM runtime: ~4:50 h
            RAM runtime: ~4:40 h


Regards, Jens

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Received on 2004-07-26