PIO
PIO, or Programmed Input/Output, is a method of transferring data from a device to another device, utilizing the computer processor and not the memory or DMA. Because PIO modes utilize the computer processor, using PIO is slower than DMA.
| PIO Mode | Max Transfer Rate | ATA Standard |
| Mode 0 | 3.3 MB | ATA |
| Mode 1 | 5.2 MB | ATA |
| Mode 2 | 8.3 MB | ATA |
| Mode 3 | 11.1 MB | ATA-2 |
| Mode 4 | 16.6 MB | ATA-2 |
Note: There are no plans, and likely will never be plans, for a PIO Mode 5 (or anything beyond Mode 4), although some computer and hardware manufacturers have advertised computer or hardware with acceptance to PIO Mode 5.
Also see: ATA, Bus mastering, DMA, Hard disk drive definitions, IDE