[comp.sys.ibm.pc.hardware] Opti-486/25 motherboard

gary@utastro.uucp (Gary Hansen) (02/13/91)

								02/12/91

	I was looking for a 386-33, 387, 8Mb caching mother board to replace
a 286-20, 287. I came across the following "deal" from a California company
called Novacor.

485-25 Opti mother board	$ 410.00
486-25 Intel uProcessor		  795.00
8Mb, 80ns memory		  432.00
128K cache board		  175.00
				--------
				$1812.00

	I have been using AMI 386-33 mark IV mother boards and have been very
pleased with them, however this is a cheaper board with about twice the
performance. 
	I am interested in this "deal" but I am vary concerned that there
may be some hidden reliability or compatibility problem that the sales people
are unaware of.
	Does any one out there know of problems with the Opti-486 chip set or
the BIOS used with it? I have been told that the BIOS is uResearch or optionally
AMI.
	I have heard rumors that as of about 3 months ago the Opti-486 would
not work properly with the Connor 100Mb IDE disk or with any VGA card running
the OAK chip set. I have not been able to get substantiation of the rumors
or find out if the problems have been solved.
	I don't want to get caught with a board that will plague me with
compatibility problems in the future. That would be no bargain at all.


	Gary Hansen
	Astronomy Dept, U of Texas @ Austin
uucp:	cs.utexas.edu!utastro!gary
arpa:	gary@astro.as.utexas.edu
at&t:	(512) 471-8414
snail:	University of Texas
	Astronomy Department
	RLM 15.308
	Austin, Texas 78712

davidsen@sixhub.UUCP (Wm E. Davidsen Jr) (02/13/91)

In article <1991Feb12.163208.29050@astro.as.utexas.edu> gary@utastro.uucp (Gary Hansen) writes:

| 	I am interested in this "deal" but I am vary concerned that there
| may be some hidden reliability or compatibility problem that the sales people
| are unaware of.

  The thing to look for in a 486 is use of burst mode between the memory
and the on chip cache. And if there's an off-chip cache, such as you
describe, the burst mode path must go all the way through.

  A system with burst mode and no external cache is faster then one with
burst mode and no external cache. And with burst mode the performance
difference from the external cache is small in most cases. I'd rather
have it than not, but external cache without burst mode will make a
ssytem barely faster than a 386.


| 	I don't want to get caught with a board that will plague me with
| compatibility problems in the future. That would be no bargain at all.

  Amen! There is a company in the back of _PC Week_ advertising a 486-25
motherboard with 512k cache for about $1600. This sounds too good to be
true, and I want someone else to spend their money proving it works
before I think seriously about it.
-- 
bill davidsen - davidsen@sixhub.uucp (uunet!crdgw1!sixhub!davidsen)
    sysop *IX BBS and Public Access UNIX
    moderator of comp.binaries.ibm.pc and 80386 mailing list
"Stupidity, like virtue, is its own reward" -me

olender@cs.colostate.edu (Kurt Olender) (02/15/91)

> Gary Hansen writes:

	   I was looking for a 386-33, 387, 8Mb caching mother board to replace
   a 286-20, 287. I came across the following "deal" from a California company
   called Novacor.

   485-25 Opti mother board	$ 410.00
   486-25 Intel uProcessor		  795.00
   8Mb, 80ns memory		  432.00
   128K cache board		  175.00
				   --------
				   $1812.00

   Does any one out there know of problems with the Opti-486 chip set or
   the BIOS used with it? 

   I have heard rumors that as of about 3 months ago the Opti-486 would not
   work properly with the Connor 100Mb IDE disk or with any VGA card running
   the OAK chip set. I have not been able to get substantiation of the rumors
   or find out if the problems have been solved.
	   I don't want to get caught with a board that will plague me with
   compatibility problems in the future. That would be no bargain at all.

>End of included message

Well, I have a Taiwanese made motherboard with just about the exact
configuration above, except that I have the AMI BIOS and I have a Conner
104MB IDE Drive, the CP-344 model.  And I have hard disk problems.
Occasionally, when copying files floppy <--> hard, it crashes the machine.
Even more infrequently, just doing a DIR will crash the machine.  But that
is extremely infrequent.  Normally, it is the floppy <--> hard transfer
that does it.

Has anyone else had similar problems?

Thanks.

jpser@cup.portal.com (John Paul Serafin) (02/18/91)

Hi,
I am also considering a system with the OPTI chipset and an AMI
bios.
Is anyone familiar with the OPTI chipset?  Any negative or positive
features?  Same for AMI bios (386/486).
I would also appreciate any pointers/recomendations on what to look
for in BIOS's and chipsets for 386's and 486's (potential memory
address conflicts, loading software into high memory, RAM that
can only be used as shadow RAM (how much, if any), etc)
I would also be interested in any experiences with I/O bus speed
and wait state combinations.
Thanks,
John Serafin
jpser@cup.portal.com