What can be done to improve ATA device performance?
A difficult question. But the first step is usually to reduce the number of interrupts that the host sees during a read or write command. ATA disk drives have three types of read/write commands: • Read Sectors / Write Sectors – These commands are the old traditional data transfer commands. These commands generate one interrupt to the host for each sector transfered. These are PIO data in and PIO data out commands which use the host processor to transfer the data. • Read Multiple / Write Multiple – These commands where defined in ATA-1 but were not used very much until recently. These commands generate one interrupt to the host for each block of sectors transfered. The number of sector per block is generally 4, 8 or 16. However, when 1 sector per block is used, these commands are the same as the Read/Write Sectors commands. These are PIO data in and PIO data out commands which use the host processor to transfer the data. • Read DMA / Write DMA – These commands where defined in ATA-1 but
