I just received this player, and was quite excited, since it supported many new formats that I have been using in the past year.

I'm happy with it, yet I wonder which format would give me the longest battery life. I'm thinking the order would be FLAC, MP3, then Ogg Vorbis, since FLAC seems to decode faster. Yet the bitrate is a lot higher. Vorbis is a battery killer, and takes a bit of time to load up. I don't want to go back to MP3, outside those files in which I have no choice but to use MP3.

I have been using Ogg Vorbis -q 6, LAME 3.90.3 --alt-preset standard, and FLAC 1.10 on best. Thanks.

I would believe FLAC would consume a lot of battery because it requires lots of disk reads.

MP3 and Vorbis files can often be loaded entirely into memory, but a FLAC file (often 3-4 times bigger than lossy files) can be loaded only partially into memory. And disk spin/read consumes quite a lot of battery.

Oh [censored].

I'll stick with Ogg Vorbis then. Thanks rjamorim.

Well, that's just a guess. I don't own a Karma.

Dunno, maybe the very low-resource decoding makes up for the disk readings.

I suggest you check out battery consumption before choosing a format.

And please report your findings to us

Will do.

about IPOD

batterytime are mainly based upon bitrates
Low bitrates = less disk reading per minut of audio, and also more minuts of audio fits into the memory buffer
In theory half bitrate mean half disk access

Even if the battery only lasted half as much in the Karma playing FLAC files, it would still last the same as an iPod playing mp3s.

I do 11+h with my karma and oggs, that's pretty damned good!

w00t, test results done.

10-11 hours with Ogg Vorbis -q6, maybe an hour more with FLAC -q5, and 15-17 with --alt-preset standard MP3. No EQ was used. Ogg Vorbis rapes the battery life at the moment, yet still beats the measly 7 or so hour battery life of the iPod.

My personal opinion, is that FLAC is not right for this player until future firmwares are released. Even after it's loaded a 35 MB FLAC file(at -q0) into the buffer, fast forwarding and rewinding through tracks takes an insanely long amount of time, so much so you may want to restart the player occasionally. You can still use it, yet I'd recommend you don't fast forward or rewind through tracks when finishing.

Also, switching between MP3s is gapless. I could have 130 MP3s set to play through, yet after 5 seconds or so, hitting next and back will have a gapless transition to the next track, even if I go through every track I have set to play. It's instant load time. With Ogg Vorbis and FLAC, it takes about a few milliseconds less than a good quality CD player does to load the next or previous track.

I'm using MP3 with this player now, since I never really realized until now, just how many hours of the day I use the player for portable music. I need 13 hours or more. I could get this at -q3 Ogg Vorbis, since the difference in decoding power needed for -q3 and -q6 on this player is quite drastic, yet I want a higher quality for this.

So, until newer firmwares come out, this is how it stands with me so far. Hope this helped someone.

Thasp, thank you for reporting this. I've been entrigued by the Rio Karma lately.

Hi can you confirm that FLAC playback autonomy is more than the ogg one???
Usually the bitrate influe on autonomy cause more high it is more disk access are neeeded...
So I'm very surprised.. Also on my iHP the wav autonomy is known to be very reduced only due to disk acces since it isnt compressed...
S i m very surpised.. Can you add some precsion?
Thanks

Go to http://www.riovolution.com and read the forums. It has already been confirmed that Ogg Vorbis takes more battery life than FLAC, and FLAC takes more battery life than MP3.

As for the seeking problems with FLAC, I remember that that is either fixed in a current or being fixed in an upcoming release of the firmware, so I wouldn't worry about that too much.