From: jim@ferkel.ucsb.edu (Jim Lick)
Subject: Re: I/O bottlenecks (was Re: New viking sparc processor?)
Organization: University of California, Santa Barbara
Date: Sun, 12 Apr 1992 03:45:17 GMT

cpcahil@virtech.uucp (Conor P. Cahill) writes:
>I'm sure they also blew away your 486 system at home with respect to cost.

Not really.  Once you add on all the things which come standard on a
Sun system, you are up around the same cost, and the 486 would have
many peripherals which would be lots slower than the Sun version.

Remember that Sun systems typically come standard with:

o High speed cpu, 16.5 to 28 mips.  Comparable to the various speed 486
  chips.

o Floating point chip.  486 includes this, 386 doesn't.

o 64k to 256k of cache.  486 itself has an 8k cache, but many 386 and 486
  motherboards have a cache.

o 8 or 16 megs of memory, upgradable to max of 32 or 64 megs on the
  motherboard, and some up to 128 megs with expansion cards.  Most 386/486
  motherboards come with 0, 1, 2, or sometimes 4 megs.  Many ISA 
  motherboards hold a max of 8 or 16 megs.  An ISA m/b can't address
  mosre than 16 megs on the bus.  It can hold over 16 megs on the mother
  board itself, but it takes some hoop jumping to actually access it,
  and this isn't supported by a lot of software. If you have some device
  which can't fit in the 640-1024k hole, you won't be able to go up to
  16 megs.  EISA motherboards tend to support 64 megs, and can have memory 
  on bus cards without kludge or performance penalty.  So it's either
  spend more on ISA, or limit your performance and memory expansion
  with an ISA bus.       

o Either a pretty quick frame buffer, or a lightning speed accelerated
  frame buffer.  On an PC type system it's likely to be an SVGA type
  adaptor which is a slug even compared to the dumb frame buffers on
  the lowest end of the Sun scale.  There are better cards available,
  but they are usually very expensive, and not well supported by
  software.

o A large 19 inch screen.  Most PC type systems use a 14" screen and
  users think 16" is a big deal.  High resolutions (1024x768 and up)
  are difficult to see clearly on 14" screens, are better at 16",
  but are only usable to their full potential on a 19" screen.

o A fast bus.  ISA is slow, EISA is in the same ballpark as Sbus.

o A SunOS license.  Currently that includes development, windowing,
  networking, NFS, etc.  On a PC, a Unix system will cost $400-2500
  depending on brand and options.  A system with the packages 
  included in SunOS is usually about $1000.

o A fast ethernet interface.  Typical ISA ethernet boards have
  trouble with dropping large packets because of small buffers.
  This is terrible to something like NFS unless you adjust packet
  sizes to something like 2048 bytes.

o A fast SCSI interface.  SCSI interface boards for ISA can't offer
  as good performance because of the bus.  EISA boards can, but you
  pay more for the bus and the better card.

o Two serial ports.  These ports can also run at high speeds (38400)
  without dropping packets.  You'll need a serial card with 16550's
  to do this on a PC system.

When you take all of these into account, price is comparable between
Sun and comparably equipped 386/486 systems.  A low end Sun costs
new less than $3000 discount.

I'll agree that it is possible to put together a 386/486 unix system
for less, but only by making compromises.  There are cases where a
386/486 makes sense, but if you are going to be spending over $3000,
you'd be insane to not compare between a 386/486 system, and a Sun.

I'm typing this from my 486 system, so they can't be all that bad.

                            Jim Lick		       
Work: University of California	| Play: 6657 El Colegio #24
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