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nslyax
Aug 17, 2003, 02:11 AM
Apple's developer documentation states:

"The Ultra DMA IDE interface, also called Ultra-DMA/33 and ATA-5, is an improved version of the EIDE interface."

and later:

"The drive uses the Ultra DMA IDE (integrated drive electronics) interface and is ATA-5 compatible. Current Data Transfer Mode for the drive is UDMA-33."

First, I though ATA-5 was 100MB/s? Second, does this mean I can't get faster than a 33MB/s transfer, even with a different HD? IBM's tech data on the 40GN states it can handle 100MB/s, so it must be the ibook's bus thats the weak link, right? Does the ATA-5 spec provide additional features beyond added speed?

mrjamin
Aug 17, 2003, 08:33 AM
Originally posted by nslyax
Apple's developer documentation states:

"The Ultra DMA IDE interface, also called Ultra-DMA/33 and ATA-5, is an improved version of the EIDE interface."

and later:

"The drive uses the Ultra DMA IDE (integrated drive electronics) interface and is ATA-5 compatible. Current Data Transfer Mode for the drive is UDMA-33."

First, I though ATA-5 was 100MB/s? Second, does this mean I can't get faster than a 33MB/s transfer, even with a different HD? IBM's tech data on the 40GN states it can handle 100MB/s, so it must be the ibook's bus thats the weak link, right? Does the ATA-5 spec provide additional features beyond added speed?

pfft. you got me!

jtown
Aug 17, 2003, 01:16 PM
Since there's no way these slow-spinning drives can sustain 33MB/s, there's no point in worrying about it. Here's an old AnandTech article (http://www.anandtech.com/storage/showdoc.html?i=1237) comparing ATA/33 and ATA/66.

BTW, just having a 100MB/sec interface doesn't make a drive capable of transferring data at 100MB/sec. The ATA specification is just that. A specification. Think of the interface as a highway. If a highway had a posted speed limit of 100MPH, that wouldn't automatically make every VW Thing capable of cruising at 100MPH. It would just mean that vehicles capable of travelling that fast would be free to do so. Currently, there's no notebook (or desktop) hard drive capable of transferring data at 100MB/sec (or even 66MB/sec). 50MB/sec is about the fastest IDE drive you're going to find right now and the current crop of notebook drives is nowhere near that speed.