[miamicanes]

Have you had any problem with PCM wavefiles stuttering, or otherwise seeming as if they were consuming disproportionate amounts of system resources when actually playing? The weirdest effect I remember seeing was that compressed files delayed, but seemed to have minimal impact on the rest of the UI or phone when playing... but playing wavfiles -- though faster to begin playing -- seemed to completely bring the whole system down on its knees.

I have a bit of a theory that might be on the right track, or totally off base:

* The phone might have limited amounts of bandwidth between system flash and system ram. Wavfiles don't need to be decompressed, but they involve more raw data to shovel between flash and ram.

* The phone is almost certainly using PIO instead of DMA to fetch data from flash into ram.

* It would (IMHO) be outrageous, but it's not inconceivable that it might have an onboard codec to do mp3 decompression in hardware, but directly bit-bang PWM via PIO. That would explain it perfectly, because THEN mp3 playback would involve feeding a low-bandwidth stream of data via PIO to the codec, vs having the CPU completely dominated trying to both shovel around large quantities of data AND intimately manage its playback (converting PCM to PWM isn't exotic, but can be computationally-intensive).