s_DSPBufferSize

The mixer engine block size in samples. Use this to adjust mixer update granularity.
(milliseconds = 1024 at 48khz = 1024 / 48000 * 1000 = 21.33 ms).
This means the mixer updates every 21.33 ms.
Usage: s_DSPBufferSize 
Default PC: 1024, PS3: ignored, Xbox360: 256, Durango: 1024, Orbis: 1024, WiiU: 1024, Mac: 1024, Linux: 1024