On Mon, 12 Aug 1996, Phil Radden wrote:
> With only a reasonable amount of fiddling I managed to get RiscBSD working
> on Cumana SCSI II and PD drive (1.1+X16, not 1.2beta) - except unixfs which
> resolutely refuses to write to anywhere without crashing the machine...
> But the main thing about it is that it is SLOW.  Very.  Even in 8Mb you are
> better off with no swap than swap on the PD, which is fair enough given the
> PD write-speed...
> But, IIRC, reading speed is comparable to HD, although seek/write is much
> slower.  Despite this, during startup etc. the system often freezes for
> extensive disk activity when it should only be reading/minimal seeking (due
> to optimisation).  Is this a lost cause, or can I improve anything?
> Obviously I'm saving for a SCSI HD... :)

  I think you'll find that the porblem isn't with the drive, but with the 
kernel driver for the Cumana SCSI II card.

  IIRC it's still in a very embrionic stage of development and doesn't 
work on interrupts but polls the card instead. This makes if very slow 
(I get no more that a few hundred K per sec transfer rate on my SCSI HD)
and a complete CPU hog. X is certainly unnusable when my SCSI disk is being
used as the mouse becomes too jerky!

  I would like to say that I think the kernel team have their priorities 
right though.  I think it's more important to get the software running 
properly with large amounts of hardware supported efficiently than to log 
every single change that happens to the WWW site.  After all everyone who 
installs RiscBSD is advised to subscribe to this mailing list, and all 
answers can be found here.... :)


Ale.