Hi,

I'm searching once again to find a way to improve disk performance with
my poor Amiga 2000 running NetBSD.  

My setup:  B2000 Rev 4.4 with 50MHz '030 Derringer
           8 Megs of 32-bit RAM (on Derringer)
           2 Megs of 16-bit RAM (SupraRAM 2000)
           1 Meg of 16-bit CHIP RAM (1MB Agnus and Super Denise)
           A2091 Rev 7.0 ROMs and 00-08 SCSI chip.
           Seagate Hawk ST31230N

I first had problems while trying to install NetBSD with the 'standard'
kernal.  I was given a patched kernal with the synchronous transfers
turned off.  I don't know if this is all that was done yet, but I believe
so.  This solved all the disk problems I was having.  But, I seem to be
having very slow disk access problems, probably due to not having a
decent driver to use a DMA buffer in 16-bit memory, copying the contents
into 32-bit memory.  This works pretty decent overall under AmigaOS.
I've achieved _minimum_ speeds of 500KB/sec under AmigaOS (max I've seen
so far is 1.3MB/sec using 'DiskSpeed').  The max throughput of the 
A2091 I've gotten in 16-bit ram is about 1.8MB/sec.  Since bustest or 
whatever it's called gave a rating of about 2.4MB/sec maximum for the 
16-bit memory, 1.8MB/sec isn't too bad. :)

I know there's some problems where 1.0 doesn't have access to the 16-bit
memory or something.  Since I'm going to upgrade to the current version
of NetBSD sometime soon, what I'm wondering, is there a new driver for
the A2091 under current?  Better yet, can I speed it up from the measly
speeds to real speeds (even as slow as 500KB/sec is, it'd be great from
what I'm getting now for normal system functions).  Or am I just better
off trying to get a 3000?  I'd rather not have to since I know (from the
AmigaOS side at least) that it's possible to get reasonable rates.

I'd appreciate any comments at all.

Thanks!

Eric

 .............................................................
.                          . Amiga 2000 50MHz '030 11MB       .
.     //  Eric K. Miller    . Amiga 500   7MHz '000 5MB       .
 .  \X/   emiller@umich.edu  . AmiTCP 4.2 / PPP / 1 Gig HD     .
 .                            . Almost there: NetBSD            .
  ...............................................................
   .    Yamaha DX7II-FD / Roland R8 / Ensoniq DP/4 / MIDI        .
   .  Coming Someday: 7 Mirage M1si's / 7 Monoblock Krells ;)    .
    .............................................................