On Wed, 13 Jan 1999, Robert M. Hyatt wrote:
> do you have a local dealer with a SIMM/DIMM tester? We ran into problems
> like this last year. Dropping a 60ns DIMM into the tester would get "safe
> at 73ns" and nonsense like that. And that obviously won't work when the
> timing is tight. We use Kingston and don't have problems.
Alas, no. Pop 'em and swap 'em are our only ways of testing. Or
perhaps I should answer maybe, and ask around...
> > e) Don't know what stage to put this, but I've found putting an
> > actual multimeter on the power supply to be helpful in the past, as well
> > as a careful check of its rated peak current/power. Some systems,
> > especially ATX systems, won't start unless the power supply can provide
> > enough current at startup, and vendors sometimes load in the cards or
> > peripherals after burning in the motherboard (idiots!) and don't realize
> > that a system built with a cheap PS won't boot. In our case, I was
> > running the lm-sensors package and already knew the core voltages and
> > temperatures to be in the nominal range.
> >
>
> a 'scope is better. You want a smooth output, not something with a
> lot of 60 hz ripple scattered everywhere. We had one of these in a Sun
> a couple of years ago and it caused random and intermittent failures that
> were a pain to find.
Scope is better, but don't have one at home. Yet, anyway.;-)
> I think one good point is to always start with 'quality' parts. IE we
> bought a bunch of Sun supersparcs last year. We have had three fail
> completely already, all three being memory problems. All three had
> memory by (I think) samson. When we have tried PC's (pentium pros and
> up) using them in heavy-duty applications like file servers and the like,
> we have had problems with off-brand memory being way out of spec. IE
> just because it says PC100 doesn't mean it works at PC100 speeds. Or
> just because it says 60ns on the actual chips, doesn't mean it will
> safely/reliably operate at 60ns. We've been considering buying a tester
> ourselves we have so many machines scattered around.
Agreed, but until a year ago I had no difficulty with Aberdeen or its
house-brand memory. A year ago my systems rep went out on maternity
leave and the whole organization (from my point of view) went to hell in
a handbasket. Some four out of four purchases from them have had one or
more significant hardware problems that are tremendously expensive in
human time to fix, even though I was microspecifying nearly every
component of the system from high quality manufacturers.
I've changed my philosophy. Now, whenever possible I deal with a local
merchant whose prices are close to mail order and can custom order me
anything I want. If I buy a system or part and it doesn't work, I drive
over, hand them the system or the part and say "this doesn't work,
fix/replace it". Then I drive back. If they want to sell my house
brand PC100 memory, it's up to them to ensure that it works flawlessly
because if linux fails to run on the system, it's almost certainly
hardware and I'll be right back in.
rgb
Robert G. Brown http://www.phy.duke.edu/~rgb/
Duke University Dept. of Physics, Box 90305
Durham, N.C. 27708-0305
Phone: 1-919-660-2567 Fax: 919-660-2525 email:[EMAIL PROTECTED]
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