Official name: Ultra DMA mode 2 (ATA/ATAPI-4 Standard)

Prerequisites:

1. Needs a system board or expansion card with ATA/33 logic.
2. ATA/33 aware operating system.
3. ATA/33 aware BIOS.

Features

1. ATA/33 has a burst transfer rate of 33 MB/s for 3 milliseconds.
2. 40% more efficient than PIO 4.
3. Uses a 40 wire ribbon cable with a 40 pin connector.

Official name: Ultra DMA mode 4 (ATA/ATAPI-5 Standard)

Prerequisites:

1. Needs a system board or expansion card with ATA/66 logic.
2. 80 wire ribbon cable.
3. DMA transfer aware operating system.
4. ATA/66 aware BIOS.

Features

1. UDMA mode 4 has a burst transfer rate of 66 MB/s for 3 milliseconds.
2. Uses a 80 wire ribbon cable with a 40 pin connector.
3. Backwards compatible to ATA/33. You can have ATA/33 and ATA/66 on the same cable.

Official name: Ultra DMA mode 5 (ATA/ATAPI-6 Standard)

Prerequisites:

1. Needs a system board or expansion card with ATA/100 logic.
2. 80 wire ribbon cable.
3. DMA transfer aware operating system.
4. ATA/100 aware BIOS.