Buffer Size

A larger block saves CPU but adds delay, a smaller one feels immediate but risks dropouts.

Related

Buffer SizeLatencyMonitoring

The question

An interface works in blocks, processing only when one fills. A large block saves CPU but reacts slowly; a small one feels immediate but breaks up.

How it works

Buffer time is block size divided by sample rate. At 48 kHz, 64 samples last about 1.3 ms and 1024 samples about 21.3 ms. The CPU must finish each block before the next arrives, or it underruns into clicks or silence. More and heavier plug-ins raise the smallest stable block.

Settings and practice

Use 64 to 128 samples for tracking, 256 to 512 for mixing, and 1024 for mastering or offline rendering. Freeze or render heavy plug-ins. Shrink the block when playing and enlarge it when exporting. If clicks appear, check CPU and drivers before raising the buffer.

What to listen for

In a funk loop, hear the hi-hat. In Alkan etudes, hear the grain of fast figures. In a jig, hear the three-beat run. Too large a block smears live playing; too small a block clicks at intervals equal to the buffer time.

Common misconceptions

A buffer is not a disk cache but the processing block of the interface. Raising it does not improve quality, only the odds against dropouts. Clicks may come from drivers or plug-ins, not a broken one. Every real-time audio path uses it, not only MIDI.

Sources

• 块大小与欠载的关系，依音频接口与宿主公开文档核查，未抄文本
• Pohlmann, Principles of Digital Audio, real-time processing sections — background checked, not quoted

Used for fact-checking only; all prose is original.