PIO and UDMA connection

The method of connection on a storage devices (harddrive and optical drive) is PIO and UDMA.PIO (Programmed I/O) is still using a biggest processing part of processor to do data transfer between harddrive and RAM.in that case, transfer PIO model is more slowly (16,6MB/s maximum). UDMA (Ultra Direct Memory Acccess) using chipset on a mainboard in order to handle data transfer so processor work not interrupt, and can work faster to processing another data source. UDMA connection is also called ATA or IDE which usually known on harddrive. Theoryticaly PIO and UDMA have a few of version which shown level of maximum transfer speed. You can see at the list bellow.

Connection                Data Transfer Rate
PIO 0                     3,3 MB/s
PIO 1                     5,2 MB/s
PIO 2                     8,3 MB/s
PIO 3                     11,1 MB/s
PIO 4                     16,6 MB/s
UDMA mode 1               25 MB/s
UDMA mode 2 (UDMA/33)     33,3 MB/s
UDMA mode 3               44,4 MB/s
UDMA mode 4 (UDMA/66)     66,6 MB/s
UDMA mode 5 (UDMA/100)    100 MB/s
UDMA mode 6 (UDMA/133)    133 MB/s