Recording Delay slider: Delays the recording of audio by a certain fixed value, helping you to compensate for any delays that are caused by the audio driver.
Note: You should not normally need to touch this setting.
Processing Threads pop-up menu: Choose the maximum number of processing threads used, or have the number of threads set automatically. Automatic is the default setting, and is recommended except when you use other CPU-intensive applications simultaneously with Logic Pro.
Process Buffer Range pop-up menu: Determines the size of the buffer used to compute mixes and effects. You can choose between Small, Medium, and Large buffer sizes.
Multithreading pop-up menu: Determines whether multithreading is set for playback tracks only, or for playback and live tracks.
Summing pop-up menu: Determines whether the Logic Pro audio engine uses double precision (64-bit) or standard precision (32-bit) buffers when summing audio. This setting applies to the Mixer, where the audio signals of all channel strips are summed together to the output channel strip. Higher precision results in greater accuracy during data processing and, therefore, delivers better-sounding results
Download the guides:
Logic Pro User Guide: PDF