UDMA

Short for Ultra-DMA and also known as Ultra ATA, UDMA is a standard developed by Quantum in conjunction with Intel that is twice as fast as the previous DMA interface. UDMA was first introduced in 1998 with the ATA-4 or ATA/ATAPI-4 standard and is capable of transferring data at 33.3 MBps, which is how the UDMA/33 or Ultra-DMA/33 names came about. Since its initial release and the approval of new ATA standards, the below UDMA standards are available.

• ATA-5 -- UDMA/66, Ultra-DMA/66

• ATA-6 -- UDMA/100, Ultra-DMA/100

Notice: UDMA/66 and higher are only supported when an 80-wire 40-pin cable is being used. This cable can be distinguished by looking at the ribbon and noticing the amount of wires when compared with a 40-wire cable.

• See our computer interface page for additional information and help with computer interfaces. 

Also see: ATA, DMA, Hard disk drive definitions