SparcStation Performance

[Charles Hedrick]

You complained that editing on the console of a Sparcstation is very slow.
You didn't say exactly how things were set up, but I think I know what is
going on.  When you work on the bare console, i.e. not in a window system,
Sparcstation 1 screen operations, e.g. scroll, are amazingly slow.  I'm
not sure why that is.  (Maybe the console emulator is written in Forth
instead of assembly?)  But if you start up a windowing system, things are
fine.  I suppose they thought that people would always use a window
system.  The only complaints we have about performance in a window system
are on color systems, which are quite slow unless the window system
supports the graphics accelerator hardware.  Fortunately the Sun-supplied
window systems do.

My only complaint about the Sparcstation is that the internal hard disks
Sun supplies are quite slow.  But with external H-P disks, a Sparcstation
seems quite snappy.  I find that the H-P disks are about a factor of two
faster than the internal Sun disks, over a variety of tests.  Our 3rd
party vendor (Boxhill) says that the internal disks are about 28msec
disks, so that's no surprise.  We have some disagreement as to whether
synchronous SCSI helps.  Sun was a bit ambiguous about synch SCSI.  Some
of the literature on the SS1 implies that it uses synch SCSI but most of
the spec's say it does not.  According to one of the header files, it is
implemented but by default turned off.  Apparently bad cables can cause
sync SCSI to misbehave badly, so they considered it safer to leave it off
pending futher evaluation.  (Oddly enough, indications are that it is by
default on for 3/80's.)  It's easy enough to turn on: 

	adb -k -w /vmunix /dev/mem scsi_options/X        ;should show 18 
	./W 38 

That changes it in the running kernel.  Use ? instead of / to make the
change permanently to /vmunix.  Use ./W 18 to go back to async.  Turning
on sync SCSI actually slows things down with the external H-P disks.
However one of our system staff (one of the few with SS1's on their desks)
claims that things start up for him much faster when SCSI is enabled on a
machine with the internal Sun disk.