[Spock@SAMSON.cadr.dialnet.symbolics.com: IFU]

[Spock <Spock@samson.cadr.dialnet.symbolics.com>]

Snail Mail Address: American Microsystems Inc. (A wholly owned
		    subsidiary of Gould Inc.) CAD Research Lab. P.O.
		    Box 967 Twain Harte, CA  95383
Phone Number:       (209)586-7422

    Date: Thu, 1 Dec 88 18:50 EST
    From: Barry Margolin <barmar@Think.COM>

    We've had LOTS of problems getting reliable IFUs and XSQs.  We started
    having trouble with one of our 3645s this summer (generally, crashes
    were the only symptom).  We replaced both boards several times, and
    continued to have problems.  We downgraded the machine to a 3640 while
    our CE tried to find us a working board set.  He kept ordering new sets,
    and he would run them in his test system for several days.  It took him
    over a month to get a set that worked reliably.

    A common problem with these, according to our CE, is getting a set of
    boards that work well together.  At the parts depot they do some testing
    of the boards, but on an individual board basis, not as whole sets.
    Sometimes different boards have slightly different tolerances, so an IFU
    that worked in the depot's test system might not work in your system.

Well, our CE kept sending us board sets that he claimed to have tested
himself and was sure that they were working properly.  Ha!  We went
through about 6 sets before our machine "worked" right.  By the way, the
machine I'm referring to is our file-server so it *can't* be down for
long.

    Our CE has also complained that the DOA rate of IFUs is around 75%.

    Unfortunately, the performance benefits of a working IFU seem to justify
    the difficulty of getting one.

						    barmar

I don't agree, I deal with CAD prototype tools (computer-chip layout,
simulation, synthesis, analysis, etc.) that can (and typically do) run
on *huge* amounts of data for days.  It's not so bad when I get an error
I can resume out of but even then I'm not assured of the integrity of my
data.  It's pretty hard (sometimes impossible) to debug a program when
the machine it's running on can randomly modify data or halt (either
into the debugger or the FEP) at any time.  And because of the run-times
I deal with you can imagine the frustration factor.  The need for
stability in my case out-weighs the need for a "faster" machine.  Hence
my mail on slug to get some sort of idea of the IFU reliablity.

Thanks for the info.