ATA bus connection ID decoder ring

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Level 1

8 points

ATA bus connection ID decoder ring

I have four identical ATA drives in my MDD FW800 machine, and I'm trying to differentiate between the ATA 66 bus and the ATA 100 bus in Disk Utility.

Disk Utility shows a "Connection ID" for each drive. Two drives are "Device 0" and two are "Device 1". Am I correct in assuming that "Device 0" is the ATA 100 controller, and "Device 1" is the ATA 66 controller?

Dual 1GHz PowerPC G4, Mac OS X (10.5.6)

Posted on Jan 31, 2009 9:12 AM

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Answer 1

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Allan Jones

Level 9

68,588 points

Jan 31, 2009 9:18 AM in response to logicprobe

Am I correct in assuming that "Device 0" is the ATA 100 controller, and "Device 1" is the ATA 66 controller?

No. I have two drives, both in the ATA100 (rear) bay, and one reports as "device 0" and the other as "device 1." Therefore it sounds like the "device n" identifier refers to the position of a drive on the cable, not the bus.

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Answer 2

logicprobe Author

Level 1

8 points

Jan 31, 2009 9:47 AM in response to Allan Jones

Thank you for that data point.

In Disk Utility if you select one of the drives (not the partition name) and click on "Info" a window pops up with various parameters, one of which is "Device tree". I have a "Device 0/1" pair on device tree "mac-io/ata-4@1f000/" and another "Device 0/1" pair on device tree "pci2/ata-6@D/".

I suspect that the "mac-io" device tree is ATA 100 and the "pci2" device tree is ATA 66. Can you confirm?

Thanks!

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Answer 3

Allan Jones

Level 9

68,588 points

Jan 31, 2009 3:35 PM in response to logicprobe

My MDD is still on Tiger and I suspect there are some differences in DU reporting. When I do Get Info from within DU, the drive on the end of the ATA 100 cable reads"

pci2/ata-6@D/@0:0

The one attached to the middle of the cable reads:

pci2/ata-6@D/@1:0

I have nothing in the ATA66 bay.

Hope this helps.

A

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Answer 4

logicprobe Author

Level 1

8 points

Jan 31, 2009 6:45 PM in response to Allan Jones

That's consistent with what I see on Leopard.

So pci2 must be the ATA 100 bus, and mac-io is the ATA 66 bus.

Thanks for the info; you saved me the time and trouble of disconnecting all but one drive and moving it around to figure this out.

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