Ide/ata/eide/dma/udma?

[confined]

I am a little confused at to what the differences between all of these are. From what I can figure out, IDE is slower than EIDE, ATA is the same as IDE but is a name used by different companies or something? So what is the deal with DMA and UDA? DMa=direct memory access right? So why would a hard drive need to access memory? Sorry if these are n00b questions, but I am a little confused at looking at some motherboards... blah. how fast is IDE and EIDE? Is there any good sites that simply all of this? thanks.

[Bmxpunk86pl]

udma is ata33 and up. its just another way of saying it. udma and ata is the same thing. IDE is the name of the type of harddrive like scsi drives are called scsi drives. and e ide is basicly faster then ide, but these days, when u buy a harddrive and it says ide, its basically saying eide because the original ide is almost extinct

[SteenkyBastage]

hey confined, welcome to the forums.

ide is the old original standard. it transfered at 8MB/sec (or close to that). EIDE came after (enhanced ide, i seem to recall) which moved the transfer rate up to 16.6MB/sec.

the ata, udma, etc are all newer transfer modes that are all capable of higher transfer rates. as stated above, they are basically interchangeable (altho i dont know they operate EXACTLY the same way, they give similar or identical results).

ata33 introduced the 33MB/sec transfer rates.

ata66 66MB/sec

ata100 100MB/sec

now the new ata133 is 133MB/sec transfer rate

note, when the motherboard/controller says it is a certain type (for example ata133), that the controller is able to accept that speed, and is backward compatible with older technology devices.

also note, when a hard drive says it is a certain type of technology (ex. ata133) that doesn't mean it will sustain 133MB/sec transfer rate. that means it should be capable of bursting at that rate, the sustained transfer rate will (at least at the current time) not come close to 133MB/sec.

you need special cable, the ata controller, and the ata drive to get the maximum results. for example, if you have an ata66 controller, and an ata133 drive, you wont be able to benefit from the ata133 technology.

[confined]

Okay, this gives me a better understanding.. Thank you for the replies.