Recent | Online | Vintage | Modern | Win | Mac  OS9 | DOS | Amiga | Atari ST | Graphics | Midi io | Sequencers | Roland "MC" | E-mu | Ensoniq | Akai MPCs | Samplers | Akai "S" | Roland "S"Synths | VST Samplers | VST Synths | Roland "JV" | Modules | Drums | Mixers | Timeline | HackintoshArtists | Graphics

Welcome to! (Online since 2014) proudly SSL-FREE! and serving vintage computers worldwide! if you are human, Register & Login to gain more access to all boards here; Some guest permissions have been limited to reduce traffic from bots and encourage registration.

Author Topic: PIO vs UDMA  (Read 2408 times)

0 Members and 2 Guests are viewing this topic.

Offline chrisNova777

  • Underground tech support agent
  • Administrator
  • Posts: 9720
  • Gender: Male
  • "Vintage MIDI Sequencing + Audio Production"
    • | vintage audio production software + hardware info
« on: December 04, 2018, 04:21:19 PM »
The difference between PIO and DMA modes

There are two modes in which data can be transferred between an ATA hard disk drive and the computers system bus, and they are PIO and DMA.

PIO - Programmed Input/Output mode is the slower of the two modes,
having the capability of transferring data at a maximum burst rate of 16.7 MBytes per second.
PIO mode is also very CPU intensive and has no built in error correction.

DMA or UDMA - Single and Multiword DMA transfers do not support CRC,
and Single Word DMA is now considered obsolete
and multiword DMA, the predecessor to Ultra DMA, was never widely implemented.

Ultra DMA, which is also referred to as Ultra ATA, incorporates a Cyclic Redundancy Check (CRC) for error detection and correction.
You can review the Mandatory Requirements for Ultra-ATA here.

The following tables indicate the associated transfer or burst rates for different modes.
« Last Edit: January 03, 2019, 11:49:07 PM by chrisNova777 »