info needed: IPI disk

[Sidney Kriger]

In article <5752 at brazos.Rice.edu> era at ncar.ucar.edu (Ed Arnold) writes:
>X-Sun-Spots-Digest: Volume 9, Issue 82, message 7
>
>...  This leaves the CDC-97209-12G
>and the CDC-97229-12G.  These are supposedly IPI-2 disk drives with a 1.2
>Gbyte unformatted capacity.

First, you had correctly identified which Seagate (acquired Imprimis from
CDC) drives were IPI-2 drives and what the distinctions were.  The
CDC-97209-12G and the CDC-97229-12G are both IPI-2 drives.  The
CDC-97209-12G operates at 3 MB/s.  The CDC-97229-12G has a burst data
transfer rate of 6 MB/s.  This drive achieves 6 MB/s by splitting the data
on WRITEs between two 3 MB/s heads as they write data in parallel to
different physical disk locations and by interleaving the data read by the
two heads back together on READs.  The unformatted capacity of each model
is 1.2 GB.

Secondly, Sun does manufacture its own IPI-2 disk controller.

IPI-2 will be available from third party vendors.  Fujitsu, Hitachi, NEC
and Seagate (alphabetical order only) all manufacture IPI-2 disk drives.
They can supply information on their IPI-2 disk drive models, capacities,
burst data transfer rates and availabilities.  Xylogics IPI-2 disk
controllers will be available from our distributors for delivery in early
May.  The SV7890 is a dual-channel IPI-2 disk controller and the SV6890 is
a single-channel model.  The dual-channel model acts like two controllers
operating in parallel, doubling the capacity and nearly doubling the
transfer rate for a single slot when compared with a single-channel
controller.  We have integrated our controllers with the four
manufacturers' drives, including the CDC-97229-12G.  Xylogics will support
IPI-2 on Sun-3 and Sun-4 platforms running SunOS 4.0 and up, although we
may limit support to certain models early on.

Sidney Kriger

Xylogics, Inc.                 email:  kriger at Xylogics.COM
53 Third Ave.                  voice:  617-272-8140
Burlington, MA  01803          fax:    617-273-5392