Reliability of Sun 3/50's

[Roy Smith]

> The question before us, as we contemplate acquisition of our sixth and
> seventh Sun 3/50-ME-4, is 'to maintain or not to maintain?'.

We have 15 3/50's, most (12) of them about 2-1/2 years old.  Call it 35
3/50-years of operation.  We don't keep any under maintenance.  We've had
1 memory chip die which required replacing the CPU board (*!$%@#!) at
something like $1300 and 30-days down-time for that particluar
workstation.  We also had a monitor high-voltage power supply die, which
we replaced directly from the monitor manufacturer (Moniterm) for a couple
$100 or so.  Right now it looks like we have a second system with a memory
chip starting to flake out (parity error panics every month or so).  We
also had a couple of infant failures, covered by warranty.

Assuming the machine with the monthly parity errors will die for good
tommorow, requiring another new CPU board, that will be under $3000 in
repair costs over 35 machine years, or $85/machine-year.

We work out the math something like this:  It costs $50/month to put a
3/50 under service.  At the time we made the decision, we had 12 3/50's so
it would have cost us $600 a month for all of them.  We can buy a brand
new 3/50 for about $3600 (educational discount), which means that even if
we had to throw one in the trash every 6 months and replace it completely,
we would break even.  As it is, we're way ahead.

Of course, if you don't get educational prices, the replacement price is
higher (but not the repair or mantenance price; there is no discount on
these).  This shifts the equation a bit.  Also, we have the technical
expertiese to do a reasonable amount of trouble-shooting and repair
ourselves.  If you don't have that, you would, for example, have had to
buy a new monitor from Sun instead of just replacing the power supply at a
fraction of the cost.  We are also able to cope with a single diskless
workstation being down for a month (Sun has priority repair service, at a
much greater cost, which we avoid).  We do keep our file servers under
contract because when they go down (hasn't happend yet!) a lot of clients
are taken along.  We also keep our 3/160's under contract because we can't
risk having to buy a new one like we can a new 3/50, and because they get
much heavier use.

Roy Smith, System Administrator
Public Health Research Institute
{allegra,philabs,cmcl2,rutgers}!phri!roy -or- phri!roy at uunet.uu.net