cpu usage way too high (?)

Nils Faerber nils.faerber at kernelconcepts.de
Sun Feb 1 16:16:28 CET 2009

Daniel Spies schrieb:
> Hello,

> I must admit that I am not that deep into hardware. I hope someone could 
> explain me why things are like this. For example if I do "apt-get update" I 
> have 100% cpu usage until it's done. Upgrade does the same.
> Recently I tried to play a .ogg file for the first time (also .mp3) and am 
> really confused about the cpu usage again. I tried to play it in vlc, but this 
> doesn't work at all. Playing in alsaplayer is nearly impossible, the song 
> laggs like hell. Only in mplayer (console version) I can listen to the song. 
> But if I do anything else, like moving a window or opending any application, 
> writing in xterm make the sound stop or lag. I can see the cpu usage is at 
> 100% all the time...
> So what my problem is: I used my old 433Mhz (33Mhz more than FR) Celeron with 
> 128MiB (same as FR) of RAM listening to music, playing games, downloading and 
> much more all at the same time and didn't have such lags. So what makes the 
> Freerunner this unresponsive and slow when doing easy tasks? 
> Thank you for enlightening me. :)
> BTW: I'm using Debian with lxde from the install.sh, but with ext3 and a 1GB 
> (*g*) swap partition on a 8GB (Class6) SD Card (and Qi).

Ah, Debian, that may explain it.
With standard Debian players you will not have much fun I assume - same
is probably true for MP3 BTW. What you need is a player that does not
use floating point - this kills performance. What is good on an x86 CPU
with explicit FPU inside the CPU is a nightmare on CPUs without FPU like
the S3C (ARM). Floating point is only supported by emulation and this is
For this reason there are fixed point optimized versions of most codecs
around, like madplay for MP3 and Tremor for Ogg.
So look for a Tremor plugin/player in Debian or compile one yourself and
CPU usage should go down to something like 30-50%.

> Best regards,
> Daniel
  nils faerber

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