Re: UDMA problems

Mark Lord (mlord@pobox.com)
Sat, 02 Jan 1999 18:11:18 -0500


> Richard Fish <rjf@estinc.com> wrote:
> > For our Seagate Medalist Pro 7200rpm drives, 18-inch cables will corrupt
> > the filesystem. The longest cable I've been able to use successfully
> > with these is a 14-inch.

The official ATA standards permit up to 18" cable per interface.
But.. if the two interfaces share some signals (data lines are
sometimes shared to save some pennies) then the total of both
interfaces must be 18" or less..

In this case, though, the bug is probably the Seagate drives.
These are ATA adaptations of SCSI drives.. not suprising they
got the electrical specs wrong for ATA. I also have a pair of those,
and mine also muck up with UDMA2.. work fine in UDMA0, though.

No noticeable or measurable performance difference between UDMA2 and UDMA0.

-- 
mlord@pobox.com
(ex IDE guy)

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