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|
There are no 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.