Ultra 33 and ATA-33

[jfchui]

This is for my old Pentium III 933 system with Windows XP, which is still good enough for my son.

The primary IDE channel has now an 80 GB Ultra 66 hard disk.
Secondary IDE channel now with a DVD drive, Ultra 33 specifications.

I need something to back up data. I prepare to attach an old hard disk to the secondary IDE channel (slave). I have the Seagate Medalist 4321, a 4.3GB with maximum internal data transfer rate of 17.5 MBps.

Simple question is: attaching such a ATA-3 disk to the same channel where the DVD drive is connected, will the latter get slowed down?

Many many thanks for years.

[Train]

No. Prior to the ATA33 specs, it would have.

[Peter M]

There is no such thing as an "ATA33" or "UDMA33" specification.

ATA - is the specification, currently at revision 8.
IDE - the physical interface.
UDMA - the name for fast transfer modes on IDE. Defined modes are 0 to 6, 16 to 133 MB/s.

So your /actual/ question is, if that old Seagate supports only lesser modes than UDMA-4 (66 MB/s), would that slow the other drive on the same cable down?

And the answer is: Yes it will, even if it /does/ do UDMA-4. This is because master and slave drives on one cable do not share bandwidth. While you access one, the other cannot be talked to at the same time. This isn't SCSI.

[jfchui]

...So your /actual/ question is, if that old Seagate supports only lesser modes than UDMA-4 (66 MB/s), would that slow the other drive on the same cable down?....


Thanks. Please clarify it more with the following:

Assume my old Seagate supports less than UDMA-4 (which is my DVD). Suppose at a particular moment, only one application is runnning. And that application uses the DVD drive, no other application is running, no other application touches the old Seagate during that time, would it or would it not slow down my application?

[Peter M]

When you're using the DVD just for viewing a DVD, then no, you wouldn't know the difference.

If the DVD drive goes at full speed however, every access to the disk drive will slow it down. This is true even if both drives support the same interface speed.