Re: [alsa-devel] Questions about virtual ALSA driver (dummy), PortAudio and full-duplex drops (playback)

While I have learned that modern cards do not have on-board buffers,

Take a look at Intel® High Definition Audio Specification Document Change Notification 4.6 Energy Efficient HD Audio (EEAudio) Mechanism

There is controller (HW) buffer <local fifo> in the Figure 14 HD Audio DMA and buffering