CPU Considerations for 3-D Buffers

Software-emulated 3-D buffers are computationally expensive. You should take this into consideration when deciding when and how to use 3-D buffers in your applications.

Use as few 3-D sounds as you can, and don't use 3-D on sounds that won't really benefit from the effect. Design your application so that it's easy to enable and disable 3-D effects on each sound. You can call the IDirectSound3DBuffer8::SetMode method with the DS3DMODE_DISABLE flag to disable 3-D processing on any 3-D sound buffer.

You can also ensure that 3-D processing is suspended on buffers that are too far away from the listener to be heard. See Minimum and Maximum Distances.