Microsoft DirectX 9.0

Using Hardware Mixing

Modern sound cards are designed to connect to the peripheral component interconnect (PCI) local bus. This bus provides the card with rapid access to system memory. As a result, it is practical for the audio processor to mix data directly from buffers in system memory, and it is unnecessary to have memory buffers on the card itself.

On PCI cards, static buffers and streaming buffers are effectively the same, and the same buffers may be reported in DSCAPS as both static and streaming buffers. The DSBCAPS_STATIC flag in DSBUFFERDESC does not affect the location of a DirectSound buffer.

The following tips will help you make the most of hardware mixing.