Cache read-ahead, or "prefetch," allows the controller, while it is reading and copying host-requested data blocks from disk into the cache, to copy additional data blocks into the cache. This increases the chance that a future request for data will be fulfilled from the cache. Cache read-ahead is important for multimedia applications that use sequential I/O.
The cache read-ahead multiplier values specify the multiplier to use to determine how many additional data blocks are read into the cache. Choosing a higher cache read-ahead multiplier might increase the cache hit percentage, however, transfer time might also increase.
For more information, see Changing Logical Drive Cache Settings on the How To tab.