I'm working on an application where I wanted to do double-buffering and tried to set the buffer size to 4096 and the period size to 2048.  However, the actual period size used by ALSA is 1365.  In fact, it seems that whatever I choose for the buffer size, the period size used by ALSA is 1/3 of the buffer size.  Is this a limitation of the audio HW that I'm using?

cat /proc/asound/cards says:

 0 [Intel          ]: HDA-Intel - HDA Intel
                      HDA Intel at 0xf8000000 irq 21