> I recently got my hands on a reasonably fast SCSI-2 drive.  On other
> platforms, I can get a sustained transfer rate of well over 3.5 MB/s on
> slow/narrow SCSI.  On my 400s, the best I've ever seen is 700 KB/s (actual
> elapsed time, not processor time).

I get 1.5 - 1.8 MB/s on a 380 with a Seagate ST32430N for what it's
worth.

> Where does the slowdown come from:  the SCSI hardware chipset in the 400,
> or the BSD drivers (i.e. will performance get better once people devote
> time to writing improved SCSI code)?

The various hp300/400 SCSI interfaces are theoretically capable of
between 2.67 and 5 MB/s in synchronous mode depending on specific
model (although at the latter speed, the DIO-II bus would be pretty
close to saturated, so "theoretically" may be the operative word).

One possible explanation for some of the difference you're seeing
here is that the NetBSD/hp300 SCSI driver doesn't allow synchronous
transfers.

-Steve