DMA..or ATA?????

[miggetyMike]

What is the difference between DMA 100 and ATA 100???

[Peter M]

Neither of these exist, so wrong question :)

ATA is the name of the specification, we're currently at rev. 6. ATA-6.

DMA is a transfer method, Ultra-DMA an enhancement of it. The highest modes specified in ATA-6 are UDMA modes 4 and 5, transferring data at 66 and 100 MByte/s respectively.

UDMA mode 6, 133 MB/s is not a ratified standard yet.

regards, Peter

[miggetyMike]

Ohhhhhhhhhhhhhhhhhhhh!!!!!!!!:D

[Ancient_Mariner]

Well, I think Mike's question was a good one. There is a lot of confusion out there about these two terms, which sometimes are used interchangably and sometimes not. More not than anything.
If they are both irrevelant, who cooked up this ATA business. We were all doing pretty well with DMA and UDMA.

Seems that technology is ruled by a partisan bunch that wants to keep the public as uninformed and confused as possible and keeps inventing new terms to that end.

[Peter M]

Well again, ATA is the name of the specification. Currently rev. 6 is the latest, with 7 in the works.

DMA and UDMA transfer modes are just that, transfer modes - they're defined in the ATA specification.

Monikers like ATA-66 or UDMA-100 are technically incorrect, yet the correct term UDMA mode 5 for 100 MB/s doesn't mean anything to anyone.

regards, Peter

[england001]

Although as has already been said, they are transfer modes - but in answer to your question, in straightforward terms - sod all - to the layman they are both the same and mean both the same. One day there just maybe one simple straightforward term for `Direct Memory Access` or `Ultra Direct Memory Access` - but until the industry gets their acts together - if you see udma 66 and uata 66 it is the same thing.