Patent ID: 7480749

Claim:
A method of operating a computer system having a processor, a disk drive including a buffer memory, and main memory, comprising the steps of: allocating a portion of the main memory as an extended disk buffer memory for use by the disk drive; determining if the extended disk buffer memory is available for storing prefetched disk drive data; if so, then sending and storing a data invalidation indication to the extended disk buffer memory; sending the prefetched disk drive data to the extended disk buffer memory; sending an associated logical block address with the prefetched disk drive data; and then sending a data validation indication to be stored with the prefetched disk drive data at the extended disk buffer memory, if not, then storing the prefetched disk drive data in the buffer memory; and copying the prefetched disk drive data first from the extended disk buffer memory only if the data validation indication is stored in the extended disk buffer memory, where checking for the presence of the data validation indication is performed both before and after copying the prefetched disk drive data from the extended disk buffer memory, otherwise accessing the prefetched disk drive data from the buffer memory.