Prefetch (cache read ahead) allows the , while it is reading and copying -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. Dynamic cache read prefetch is important for multimedia applications that use sequential I/O.
By enabling dynamic cache read prefetch you can use the built-in prefetch capabilities of the RAID controller module.
For more information, see Changing Virtual Disk Cache Settings on the How To tab.